I can see why you would like them when they are tuned correctly but I prefer manual all day for track duties.
I took my JTS sele to the track too. I actually enjoyed it and would prefer it to a manual. Now my car had some issues, one being that previous owners destroyed 3rd gear syncros while driving with semi-broken selespeed, and that JTS is weaker than TS when as is. Both issues can be addressed, but I can't be bothered, especially so that I'm going to race another car next season.
So as for selespeed on the track.
Pros:
1. Never a misshift. I certainly lost a few good laps to getting lost between gears.
2. Rev matching downshifts with no effort. This is a big one - I can't heel-toe so downshifts are rough and take attention off the track. Click and forget is so much better, not to mention the buttery smooth rev matching.
Cons:
1. Upshifts on its own when hits the limiter.
2. The limiter is 5000 rpm lower.
3. Requires some periodical maintenance and possibly repairs. This a minor one, as once you set it up once, you're good for quite some time.
And while its upshifts don't feel quick, it seems like they are on par with a manual.
