I had a 2005 DL1000 which had fueling problems. The bike either ran great or terrible, and I had no way of knowing which it would be on any given day. It had several problems (besides fueling) which were not deal breakers, but were annoying: clutch chudder, buffeting, lurched off the line in 1st. I had a retaining clip on the rear brake line come loose which allowed the brake line to contact the exhaust plumbing. The brake line burned thru, dumping brake fluid on the hot exhaust pipe... fire... 45 minutes into a 3 day-trip. Turn signals broke every time it was dropped (even WITH crashbars). First gear was way too tall, 6th gear required breaking the law.
So, it was often frustrating, but when everything "clicked", it was a fantastically fun bike. It was great for long distance on the highway, great for camping (hauled lots of gear), a little too much for offroad for me at the time.
Coming to the S10 via another Strom (a 650 - big mistake for me) was a big step up. The S10 is just a better bike: better brakes, ABS, linked brakes, better suspension, drive shaft, stuff standard that had to be added to the Strom (center stand, 12V outlet, e.g.). It inspires more confidence off road for me.
I never rode a Gen II DL1000 - in part because I was afraid I'd fall in love with the engine and the handling characteristics and I REALLY wanted a shaft-drive bike. I think on-road zipping around, the VStrom might just edge out the S10 for fun. Reliability, comfort, off road, low maintenance, the S10 wins in my book.