Been giving this a bit of thought and I'm bored so I figured I'd pen some of my thoughts on the 3 bikes I've had at the track in the last year or so.

The bikes:
04 SV650S, relevant modifications: Elka 2 way shock, 07 GSXR 750 complete front end (OE internals though the OE spring rate is about right for my weight), no stabilizer, OE GSXR brakes w/SS lines and EBC HH. Full M4 system, no tuning

04 GSX-R600, relevant modifications: Penske 2 way shock, Racetech fork internals set up for my rider weight, OE stabilizer, Brembo RCS w/SS lines and Vesrah, Yosh slip, PCIII custom tune.

07 Daytona 675, relevant modifications: Penske 2 way shock, Penske 20mm kit forks, PitBull stabilizer, Brembo RCS w/SS lines and Carbone Loraine, Full Leo system, TuneBoy custom tune.

All bikes with stock motors and typical track goodies like rearsets, clip-ons, etc. I've run all 3 on Pirelli SuperCorsas SC1/SC2 combo. I've run all 3 at Beaver so I can probably do a bit of an apples to apples comparison.

Power: Obvious looser in total numbers is the SV. There is no obvious winner in top end as I think the Gix and the 675 put out pretty similar numbers on top. The 675 has a torque curve that's very similar to the SV with the big exception that it does not run out of breath at 8,500rpm and pulls strong all the way to the red line. The Gix is down on power in lower RPM's to either of the other 2 bikes BUT it has a harder hit on top than either. Keep it above 10k or so and it pulls like mad. It's much more sensitive to where you are in the rpms than the 675 or the SV. It feels like it's stronger on top than the 675 from a seat of the pants prospective but I do not believe that is actually the case. The feeling is a manifestation of how the I4 delivers power rather than actual numbers.
On motor I think the 675 is the clear winner. Linear torque curve all the way through the range provides more predictable power delivery to the rear wheel. I think this bike ends up getting better traction coming off a turn than an I4 because of this. There is none of the MX like power surge on top that takes the bike from nothing to warp speed in an instant like a typical small I4. The motor breeds a great degree of confidence in rear wheel traction. It will also pull with the Gix down the straights. Though I think the Gix probably has a hair more top end potential, particularly a well tuned one like what Lee just bought, I find the flat torque curve more appealing. The SV's motor is very similar from a seat-of-the-pants perspective to the 675, right up until it runs out of breath. There is certainly something to be said about the additional 40 or so HP the Daytona brings to the table.

Handling: I'm somewhat torn on this one. My SV was VERY well sorted out and bred a huge degree of confidence in the corners. It was likely the most "flickable" of the 3 and probably tipped in better than the other two. It was not overly stable in high speed turns, likely due to the decreased wheelbase from stock and increased rake of my Gix front end swap. I never had a stabilizer on it and it probably could have used one. The feedback from the front end was overall good though the back felt a bit numb.
The GSXR on the other hand is probably the slowest to initiate into a turn and required the most work to change direction but it is also the most stable at speed of the 3. The bike is just plain solid once set into a turn. Almost unflappable inspiring a huge degree of confidence at triple digit speeds. It has the OE stabilizer on it and could probably use something better. I got some pretty hasty head shake coming on to the straight at Nelson. I was also likely grabbing on too hard exacerbating the issue. I think the Gix has the least feedback of the three. It just feels planted but it does not "talk" back as to why.
The 675 sort of splits the difference. It is as quick or almost as quick to change direction and tip in as the SV and almost as stable as the GSXR in high speed turns. It has the most extensive suspension work of the 3 and it was done by MotoCD who specializes in setting up 675's and it clearly shows. I did have to clamp down a bit on the stabilizer, particularly when coming off T8 at Beaver into the sketchy stuff on the outside. The bike has that almost telepathic quality that my SV had. It took a very short amount of time to sort things out and the feedback from both ends was excellent, probably best of the 3.

Brakes: Since I had very similar set ups on the SV and the Gix the brakes felt pretty similar though the RCS I ran on the GSXR is certainly miles ahead of the Nissen GSXR master I had on the SV. I like the Vesrah pads in the GSXR better than EBC HH's. The GSXR was probably the most stable under braking of the 3 bikes. The SV and the 675 have a stronger tendency to get light and a bit wooly in the back than the GSXR. The jury for me is still out on the CL pads in the 675. I think that I was more comfortable braking deep into a turn on the SV than either of the other bikes. I believe the engine braking of the v-twin had a lot to with. The 675 freewheels a lot like an I4.

Ergos: The GSXR has the most relaxed ergos of the 3. You tend to sit "in the bike" rather than "on top of the bike" like you do on both the SV and 675. My SV had clip-ons so it was pretty low in the front. The 675 feels to be the smallest and lightest of the 3 - which is actually is as well. It had that small bike feel like the SV that I really like. The tank is shorter on the 675 than either of the other two and it makes it easier not to hump the tank. The 675's ergos over all are the most aggressive of the 3. To me the 675 just fells right after getting acquainted. The GSXR just feels big to me, it feels to be almost exactly as big as my R1 though on paper it's about exactly the same weight as the SV. Some people are more comfortable with the wider, more "substantial" feel of the GSXR. The whole ergo thing is very personal but for me the ergo list would be 675, SV, GSXR - at least for track use. I'm guessing for street the GSXR would be easily the most comfortable of the bunch, at least with the way my bikes are set up.

So in the end there really is no perfect bike out of the 3. I think the SV is about the ideal track starter bike and I've seen plenty of them running in NESBA A groups so it's obviously enough for most mere mortals. Mook, Scott Rosey, told me he turns 1:01's around Beaver on his - I could not do that with a JATO pack attached to my ass so go figure. The thing about the SV is that it never really scares you, it's always predictable from the way it turns to the way the power comes on. It teaches you to carry corner speed and work the brakes since that's the only way you can keep up. The old axiom that says that it's more fun to be fast on a slow bike than slow on a fast one is so very true. When I rode with STT last year and could make inside passes on liter bikes with the SV it was an absolute blast.
The GSXR is sort of a "McBike", it is what it is and it does everything reasonably well. Like Jason Karns once told me, it's the Chevy of the motorcycle world. It's easy to ride, easy to maintain, easy to fix. It takes some getting used to the power band and to the "big" feel of the thing but in the end it's a good bike and for people that like it's ergos and power delivery it's a great machine.
The 675 is just about right, great motor, great underpinnings, great ergos for me. The bike just feels about perfect to me. I was 3 seconds faster than ever around Beaver on it by my 5th session on the bike. It's very much like the SV in many way BUT with an extra 40hp. It can flick in and out with the little twin but keep up down the straights with 600's - it's almost the perfect combo. Sure it's a bit cantankerous to work on and maintain and yes it's a bit more expensive but honestly I'm just about in love with the thing. I haven't had as much fun at the track since I sold the SV last year as I did on the 675. I think that I've found the perfect trackwhore for me. But the important part is the "for me" - your mileage may vary.

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