I have heard that it's limited as far as what loads will work well, but that's third hand internet chatter. The MecTec is straight blowback, so really hot loads may blow it open harder than you want them to. That said, those I've talked to (online) who have them say they are the bee's knees if you feed them what the manufacturer recommends.
There aren't may options out there for carbines in 10mm. Too bad, because it's a great cartridge and I think lends itself well to a carbine. The MecTec is probably the most cost effective way into a ten mill shoulder arm. Please keep us posted. I'd love to hear more about these.