Maligned in its day for vague steering (remedied by swapping the 60-section front for a 70-section, raising the front mudguard to improve clearance and dropping the forks through the yokes by 8-10mm) the screaming motor, sharp looks, compact dimensions and overall fun for riding and owning are the key reasons to buy.
This particular model had a few styling updates over the original R6, but shared the same razor-sharp chassis and screaming motor. Steering can get twitchy if ridden hard on bumpy roads but that's true of all early-Noughties sports bikes. Powerful (dynos show around 100bhp - 120 is a claimed crank figure) with a decent spread of torque.
With figures like that coming from the motor, and given the calibre of rider often attracted to Yamaha's supersport screamer, wheelie abuse is inevitable so check for the tell-tale signs - knackered steering head bearings and weeping fork seals. Scraped pegs will indicate track use; you'd be hard pushed to deck out an R6 on the road.
Brakes were highly rated when new, but things move on and now they're rated 'okay'. And the passage of time isn't kind to Yamaha's OE stoppers, so maintenance is required to keep them sharp.
With tons of aftermarket parts available, owners' tastes are often stamped on their bikes. Expertly-fitted, quality add-ons such as aftermarket suspension parts and a race pipe or can are to be expected, but always ask for the standard bits. The R6 is the 600 of choice in the R&B fraternity too, so don't be surprised to find bikes adorned with tasteless anodised bling. Again, ask for standard parts when buying.
Out in the real world comfort is passable even over some distance, but round town it isn't such a breeze and full lock U-turns are awkward. It's a small price to pay.
Key ID: white LED rear lights distinguish it from the earlier R6
Walk away: if the owner has a pile of shagged tyres and crash damaged leathers