I picked up one of the new flat tops for my son last weekend at Cabelas in Saskatoon, along with a spare magazine. We got out to the range this afternoon and put a Federal Champion bulk pack through it and I have to say I'm surprisingly impressed.
The stock feels sturdier to me than some of the early carry-handle versions I've fondled, and although the mag release seems ill-concieved it worked fine. The sights were easy to adjust and gave very positive clicky feedback, and a 1" square of duct tape on the tube got rid of any rattle from the M4-style stock. It's light, fast-handling and easy to run.
Accuracy was decent (we were using irons so we weren't really pushing the envelope) and reliability was quite good. Out of 525 rounds we had only one malfunction, a FTE, and that included several mag dumps as fast as he could pull the trigger. My son's range report consists of "I love it! It's awesome!" which is enough to put a grin on both our faces.