I am planning a 9mm build (NY compliant) and am trying to decide on a platform.
I am thinking of a CMMG lower that uses SMG mags.  ASC has cheap 10 rounders.  Has anyone had any experience, good or bad with this setup?
The other option is a Lone Wolf Glock setup. Is this route worth the extra couple hundred semolians.

I've got a Hahn precision permanent block and it does not like the mags Aim surplus sells.  I get all sorts of FTF and FTE issues when I'm using the two C products 20rd mags I have.  My 9mm AR runs without issue with metalform mags.  

It does appear that which magwell block you use will impact which mags work, so YMMV depending on which block you pic.  I know some folks have had good luck with C-products ones, but that hasn't been the case for me.

My plan is to go with a lower designed to use the mags, so no mag well adapter would be needed.

I have a Cmmg dedicated lower and have been using nothing but ASC mags.

I have a dozen or so 32rd mags that have been FLAWLESS, but I ordered 3- 20rd and 1- 10rd mag a few weeks back and had to file one feed lip on each of them to get them to work with the Cmmg bolt. It took less than 2 minutes per mag but I was miffed that my 32rders are fine and the smaller ones needed a little fitting. Function past that has been fine.

If you already have a Glock and have the mags, go with the Lone Wolf.  If not, then either one is fine.  The Lone Wolf does not have a BHO if that matters to you.  I went with the CMMG lower and it works perfectly fine, I haven't used the ASC mags.

ASC mags run 100% in my DDLES Colt style lower.

I have a factory RRA 9mm carbine, and I built a 9mm upper for my SBR.  With the RRA block, I had to tweak the block position just a bit to get it to run 100% with:
OLD CProducts magazines
Metalform magazines
RRA converted Uzi magazines

...all three types of mags run fine with the block in the appropriate position.  I'm not going to say I'm lucky, but I haven't seen a lot of positive comments about the old CPro mags - they were inconsistent in assembly and had poor QC, particularly at the end.  The only one that gave me trouble was one I dropped, full, onto the feed lips.

My advice is to buy two of every kind you can find (except ProMag's plastic ones - they have always been too soft to handle full loads) and try them out.  You can find Metalform 9mm Colt-style AR magazines at CDNN for a pretty good price when they're in stock.  

The NEW CProducts Defense is a completely different company that owns the intellectual property from the old company; they use a lot of robotics in manufacturing their mags, which makes them much more consistent the old company's products, and they're still reasonably priced.  ASC is a firm made up of former (old) CProducts employees who bought some of the intellectual property and most of the tooling of the old company.  I don't know if they use robots or not, but they seem to make reliable magazines.