I'm looking at buying a 600cc track bike and most have been in the 2003-2010 range. Does brand matter when looking for a track bike of that age? Ar there some to stay away from... are there ones to seek out?
In my opinion, the most important thing is to find a well cared for example that already is set-up with all of the goodies for the track. Any of the big-4 Japanese bikes will be fine. Having said that, the 2006+ Yamaha R6 is the most popular bike as it is largely unchanged and still considered one of the best (most competitive) 600cc track packages.
I’d look for one with a suspension set up for your weight. That will be more important than brand. Any of the bikes put out by the major manufacturers will be decently reliable.
Avoid the 2006/2007 Yamaha R6. The motors tend to go bang. On that note, I cannot reccomend the 2nd generation (03'-05') R6 enough!! Reliable, fast, cheap, stable/planted front end feeling.....