I couldn't cope with any of the other mag fed designs - could be I'm just crack handed but I couldn't get any decent reloads, getting the angle wrong, fumbling the reload, breaking paint
With the dam it's just straight in easy
Best Mags?..... 10 round tubes in a cram and jam setup ha!. But seriously I'd have to say Zeta's if you want good mags but yeah the Dam mags are also good. One point against the Zeta's is that they use a brittle plastic. If you accidently let the follower fly up with no balls in the follower can and will be disintigrated. Now this would be fine if it was user error but all the times this happened to me was just before I would fill up a mag and the follower would become unlocked from the part that holds the follower down allowing it to shoot up and smash itself to pieces.
When they work they work well but they sometimes fail. Out of the 10 zeta's I have 4 of them have done this.
If the Dye mags don't suffer from this issue then go Dye.
However please note my Zeta's are all Gen2 so this may have been fixed.
My mag fed experience is quite limited but I've been consistently impressed with DAM mags. They are durable, consistent and also really really affordable. They are quite bulky though and they aren't particularly high capacity.
Really looking forward to seeing what you come up with Renie. As for which Magwell to go for, might be worth taking into account if you'd like to use drum/box mags with it... in which case Milsig have come out with the tempest drum mag which looks really cool, works with their m17 smg magwells but also works with the tpx apparently