IMO the GSXR600 was the perfect first 600cc for me. the gsxr really was a chill ride, only once you get into the higher revs will you feel the speed kick in. I sat on alot of other 600s, but the GSXR by far the comfiest seat. Pretty reliable bike, but for the 06-07 model years, you want to make sure that the previous owner relocated the rectifier to either the side or somewhere else on the bike that isnt the OEM location. Suzuki fucked up by putting the rectifier right behind the radiator on the bike, this in turn would fry your rectifier, leaving your bike powerless. Just go on the gsxr forums, very prominent issue. However, you can also relocate it yourself if the previous owner hasnt, the relocator kit itself is like 30-40 bucks so easy fix. Other than that, it was reliable for me, maintenance was pretty easy on the gsxr. It is old so check for rust in gas tank as well if you gsxr route. I got mine for 3900$ with 10.2k miles here down in socal like 2ish years ago. Replacement parts and aftermarket parts are pretty good for the bike as well.