The Mini-Me, as I understand it, is one of the least stable crafts you can take down a river. They are a hoot and tons of fun, but very prone to tipping over. I haven't tried any of these small craft but I've been around them some, and the general consensus I've heard is that the paddle cat variants are quite stable for their size and less prone to flippage compared to a boat like the Mini-Me. I've been considering an Aire Sabertooth lately, but having been a kayaker in years past I'm up in the air on whether I want to get one of those or just get back into one of the kayaks I have hanging up in the Garage. Good reasons for both ways though and I wouldn't be surprised to see a paddle cat style boat in my quiver in the next couple years.
My estimation of using a Dory is they are great for big water where hitting rocks is less of a problem, but even the decked ones are prone to filling up with water(even if its just the captains and passenger footwells). Definitely ways to mitigate this, but I'm told they become quite hard to manuever when they are full of water. They look like a hoot and I'd love to row one down one of the higher volume desert rivers some time, but not sure I'd be pushing my limits on stuff like the Lochsa in one.