I own an '03 model R6, which is almost identical to the current R6s. Love love love it. Put 21k street miles on it in 3 years mostly commuting to work, a few 300+ mile day rides, and one track day.
I have also ridden my friends '02 SV650. I haven't ridden the current generation, but I don't think they are that different. Riding the SV is what convinced me that I needed a V-twin, and consequently led me to the Tuono.
The SV is narrower, lighter, and almost felt like a bicycle or dirtbike in comparison to the Yamaha. I was amazed at how easy it was to flop over into turns, and thanks to the V-twin torque, how peppy it was leaving a stop. To me, the R6 feels more stable, though, and feels much much faster once you really twist the go-fast lever and get up into the peak power.
The low fuel light on the R6 comes on somewhere between 106 and 125 miles. The seat is comfy for a supersport. When stuck in traffic for extended periods of time in the middle of summer in Arizona, the right side of the frame would get very, very hot, and transmit the heat into the right footpeg, making for a toasty foot. Storage space is minimal, but that's what tankbags are for. On-off throttle response can be kind of abrupt, but they may have fixed that on the new ones.
I had to replace the ignition coils at 8k miles, due to a defect they had in '03. This ONLY affects '03s.
I replaced the chain and sprockets at 18k miles.
At 19k miles, the Throttle Position Sensor went kaput. $75 part. This is a typical Yamaha problem.
After I bought the Aprilia, the R6 was relegated to "backup" duty. It sat in my garage neglected for 8 months before I rode it again. The (still original) battery needed charged, the throttle and idle set cables needed lubed, and the tires were a bit low on air. That's it. It fired right up, and it was like I had never stopped riding it. ('Cept the Tuono makes IT feel like a bicycle.. heh.)