the flex that he's talking about is a da, just like the porter cable... the difference is that the portercable is a random orbit da where the flex is a direct drive da, so this also makes the flex rotate as it does it's dual action but rotation is not the cutting method, it is not really a rotary and it does not cut anything like a rotary, I use a rotary all the time myself but I got a chance to check out soons new flex and I gotta say that it really is a nice machine, def not aggressive like a rotary but not wimpy at all.. in the past I've tried other da's and honestly I've found the ones I've tried to be kind of wimpy, great for buffing and polishing waxes and stuff, light buffing, but wimpy when it comes to paint correction, but I have not tried the portercable unit itself, only assume it to be similar to other random orbit da's... with most random orbit da's the da action can be affected and even partially halted by pressure where the flex can't because it is direct drive but it is def a da not a rotary
truth is if you already have the portercable and it's doing the job for you I'm not sure if I'd run out and sell it to get the flex, if your ever out my way on a friday evening then maybe you can bring your portercable by and I'll get soon to bring his flex and we can side by side them to see...
of course there are other models of flex units that are rotary too, I'm guessing brad is thinking more about one of those, the flex DA is relatively new...