Mine has held up pretty well and it's been drug around a bunch. But it doesn't have the pedal drive. I just use a paddle.
I don't stand in mine. I used to fall out of a bassboat all the time so I know I'm going over in a kayak. But it is very stable. I've screwed up on some pretty good runs on the river and just knew I was going to flip, but I never have. Some of them are very stable. My biggest issue is getting in and out or on and off if you want to call it that. It would be easier if I was in better shape probably. But my seat sits really low. I think raising it or buying a different yak with a higher seat would help a lot.