I have a '99 B12 and an '03 DL1000. For the kind of riding you describe, either one would do just fine. The Bandit has a little more sporty riding position and geometry. The DL sits me a little more upright and has more leg room, but aggressive cornering will have the footpegs grinding a little earlier than I like. The Strom also requires a little more effert to turn in and hold a cornering line. With an aftermarket windscreen, the Bandit keeps most of the wind off of my torso. The wind that reaches my helmet is noisy, but there's no buffeting. The Strom has a lot aftermarket screens available in various sizes. The biggest problem with it is finding one that doesn't buffet your helmet. This is mostly because of the distance between the rider and the shield. The BMW-GS and other bikes have this same problem. Both bikes have plently of power and torque with the Bandit edging out the Strom. The V-Strom is deceptively fast though. When I first rode it after jumping off my KLR, I found myself going a lot faster and accelerating alot harder than I thought I was. I do like the character of the Bandit motor a little more than the big v-twin, but I've read posts on the V-Strom boards stating the opposite. But, I think the 650 v-twin has more character than it's bigger brother and a lot of magazine testers agree with me on this point. Still, I'm happy with both. Both motors need an aftermarket exhaust to really excite viscerally, with the Bandit being cheaper to upgrade with it's one muffler. The big Bandit also responds better to an aftermarket muffler (makes more power). As mentioned previously, the big Strom does stutter between 3-4000 rpms. This is caused by a fuel-injection glitch in all year models, that got worse with some of the '06 models. There are aftermarket fixes for this. Some of them relatively cheap. Read up on it on vstrom.info. (The DL650 has no fuel injection issues and neither does the new 1250 Bandit.) In the 2002 and early 2003 models there was also a problem with the clutch basket causing "chudder" in the same rpm range. My bike had both problems. A power commander made it better, but the clutch chudder is still there although I don't find it annoying enough to spring for a later model clutch basket. Also, many people, including me, found the stock handlebars on the Stroms to be angled too far back causing discomfort in the wrists.
Which one to get? Which ever one excites you more. The Strom is more versatile with respect to the kind of terrain you can travel and can be more touring friendly. It does, however, have a few more quirks to sort out than the Bandit. But, if you know that going in, it not a big problem. The Bandit can be set up a little sportier or can be made to ride more upright depending on your preference. Hope this helps.