I can help a little on the handling and rain. I've done 200 miles in rain with some torrential bursts. It does fine, wear the proper gear, take corners slow. Rain on the windshield wasn't a big deal for me, as I see over it. The wind and rain is mostly directed over the helmet (I'm 5'11). I was very comfortable, other than I was wearing summer gloves, so my hands eventually got wet. My, hands, knees and thighs took the brunt. If it's not bitter cold, I find I have fun in the rain. It feels more adventuresome, but maybe I'm odd that way. I also ride a lot of cross country dirt bike stuff, so maybe I'm use to it.
I'm blown away by the handling on the bike. I've cornered so hard that I have pavement scrapes on my pipe cover on one side, and I've scraped the kick stand going the other way. I've lost a few motorcycle riders who couldn't hang through the corners with me. Granted, it gets a little squirrely when doing so. Soft suspension and small back tire. And I wouldn't necessarily recommend corning so hard, but I've been riding for a long time, including sport bikes. And I ride with all kinds of armor on, even when I'm going short distances. Not that that excuses any stupidity on my part. Don't skimp on safety equipment! Look for at least a Snell rated helmet, and I ride with a pressure suit too. Acerbis makes some nice mesh ones for hot weather, the Koerta line. They also fit well under my cold weather gear.
Having the seat back another two inches would go a long, long way for me in comfort. Still, It's more comfy than any motorcycle I've owned. The only other scoot/motorcycle that holds my attention is the upcoming BMW C600 Sport, possibly the BMWF800, but adventure bikes can't corner very well and make horrible commuters. But lets face it, the BMW will be a lot more expensive, and I'm doubtful the MPG's will be as good. I'd steer clear of smaller scoots, you'll just find yourself wanting more. The DT is a very nibble and light bike with a low seat height. Affordable and great for learning.
