I had an '02 DL1000 V-Strom before I got my Fazer. The new ones are no faster. The good part was that there was pretty much always sufficient thrust available at any reasonable engine speed from 4000 rpm up, whereas the FZ8/Fazer has a flattish spot from 5000-6000 rpm, and is not as strong in the midrange generally (giving up 200cc in displacement will do that). And it was quite a bit more comfortable than my Fazer, even the stock seat which is like a comfy chair compared to the torture pad that Yamaha put on the FZ (IMO).
The downside was the sloppier handling that came with a larger, slightly heavier, taller, longer suspended bike. Just not as nimble in the tight twisties.
So I've done the V-Strom thing and probably won't go back right away. I'd be interested in the FJ-09, but apparently it suffers from the same bargain front suspension as the FZ-09. Front suspension is expensive and/or labour-intensive to fix.
The Ducati Multistrada would probably also interest me. I don't really need that kind of peak power, but undoubtedly it also has gobs of midrange. And better suspension and handing overall compared to the V-Strom.
Anything with a more aggressive riding position, or less wind protection than my Fazer 8 is out of the question, for me. I'm actually thinking about getting the big Givi screen for my Fazer.
The biggest shortcoming of the Fazer for me is long-distance comfort. The seat, even the Shad seat I got for it, just doesn't cut it. The tighter seat-peg distance doesn't help, either. But the question is, what can I go to that is more comfortable, but also handles as well and is just as exciting to ride? Probably I just want the impossible - big sport-touring (or Goldwing) bike comfort on the straights, but sport bike handling in the twisties. Oh, and also not too huge so as not to take up too much space in my garage.
More performance? I really don't need it - riding the Fazer hard is already putting my license is serious jeopardy.