I consider myself an AR newbie, but have fired M16's in the service 35 years ago, and owned an SP1 before the AW ban, and a buddy talked me out of it..
I recently traded into an Olympic Arms AR15 carbine in 9mm with dedicated lower.. I liked it because it uses standard Glock mags, which are cheap and plentyful..It came with a bunch of 32 round mags, but I have since bought a few 17 round mags.. They make shooting from a rest easier..
The Oly shoots very well, and I have not seen it fail to fire in any of the hundred or so rounds my buddy, my daughter and I have put down the barrel so far.. The lower would fail to hold the bolt open after the last round when I got the rifle, but this turned out to be a loose screw which holds down the link which actuates the bolt hold back..
Now to find out if a 40 S&W top will work with my lower.. Obviously different mags, but I think I would like a 40 S&W over the 9mm..
flk k