I, too, am 5'10", 30" inseam, about 200lbs., and the dr200 is not too small for me but I'm glad it's not any smaller. I don't get off-road with it, don't ride aggressively, and am content with it's placid speeds. However, inside 30 minutes on the bike and my posterior is uncomfortable.
I like nearly everything about this little bike but seat comfort may end up being a deal-killer for me. In the attached pic (along the Salmon River just south of Cottonwood, Idaho) you'll notice the usually purple seat is covered by the much-discussed Walmart seat pad. I wish it improved the seat's comfort level for me but it doesn't much.
I don't need car-like comfort, but when trying to get comfortable becomes the main focus of the ride after just 20 minutes or so the fun starts fading fast. I'm sure my 55 year old butt just doesn't tolerate what it used to 40 years ago, and I know comfort is a subjective and personal issue. Still, there's got to be something out there that's better than this!