They're OK. I own both and don't think I'd buy another para, but I'm glad to have the one I have.
They're not that compact when folded due to the width of the stock - nothing like a slim AK sidefolder. And they're not bad, but they're not all that comfortable, either.
They also get in the way of the trigger when folded. You can reach it, but it's uncomfortable. Of course, if you don't intend to shoot it with the stock folded it's not an issue.
Lastly, I'm not a big fan of DSA's scope mount since it mars the reciever and I've heard of the screws stripping or the plates working loose. But DSA's mount is the only one that I know of that allows you to remove the para's unique recoil sping/carrier/bolt setup without removing the scope mount. I don't know that Arms or Leapers mounts will return to zero when removed for cleaning, but when I get the money to throw an EOtech on my para 16"er, I think I'm giving the ARMS mount a shot.