To answer your question, “anyone close to my size has any experience on a Blast – and what it’s like with respect to comfort,” I stand 6’1″ and 200 lbs. I have 3700 miles on my Blast and have no trouble with comfort–I have the standard seat, not the low seat. The bike is perfect for my 20-minute commute and extremely fun to ride around on during the weekends. I have ridden it on the interstates and highways, but its lack of weight makes it not fun to fight the winds at interstate speeds. It is extremely fun to ride on the twisty roads where I live.