They are very different then the old ones. The impeller is a directional design. There is a little tab that prevents it from running in the opposite direction. I don't they're good for repeated start/stops, but for general use, they seem to work good. I've had one in my 90gal now for almost 6 months and haven't had any issues. Turn it off about once a month when I do my water change, but haven't had any of the "old Rio problems" I expected with it not restarting. It also seems to be a lot sturdier construction then the old ones. I have also never cleaned it and it's just kept on running great.
Oh yeah, for the record, someone actually sent me one by mistake and told be just to "keep it". Since I had a free pump, I figured I'd try it just for the heck of it. Like I said, I've only used it now for about 6 months, but I can't complain at all.