I’ve had my black GSX650F for almost 3 trouble-free years now (35,000+ miles).
I like it a lot as it’s fast enough to be entertaining without being crazy fast (will do 130+ mph I’m told). It feels very stable and safe at speed, nice, almost upright seating position, but has a long seat so’s you can crouch sport-bike like if conditions dictate. It’s heavy enough not to get blown around in high winds, has twin-like torque (which means that you’re not constantly changing gears to keep the engine within a narrow power band (like on the now obsolete FZ6)), and it won’t go into unintentional wheelie’s on you. Looks like a GSX-R too if you’re into that sort of thing.
I actually went to the dealer ready to buy a V-Strom 650, but I ended up with this instead after having sat on them both. This was just more comfortable (and doesn’t make you look like you’re sitting on a carousel horse).
For perspective, this was the third motorcycle I’ve owned after a Nighthawk 250 and a 2006 Triumph Bonneville. I primarily use it for my daily commute (~32 miles each way); much of it on the freeway.