First thoughts on the Masada ACR:
(I have the FDE version)

Pros:
real trademarks
awesome looking rifle
perfect for right and left handed shooters (or switching to your "weak" side)
build quality/materials are excellent
alot of room for a battery
quick change spring
comes in black, flat dark earth and foliage green
quick detach barrel assy
magazines are easy to maintain
easy disassembly with minimal tools required
compatible with most Tokyo Marui type mags

Cons:
somewhat expensive
front hand guard looks kinda big
plastic flashhider (super glued on)
CW flashhider threads (most AEG's are CCW)
doesn't come with foldable stock
low FPS (310 FPS with .25) out of the box
no tools included
Magpul PTS P-mags are expensive

Haven't played with it yet. I did put a M120 spring in it and the FPS jumped to 380 FPS with .25's.
The quick change spring is a very nice idea. It would have been nice if Magpul included an allen wrench to change the spring. I don't know what size it is (5mm or 6mm?). I used a flat head screwdriver, but an allen wrench will be easier to use. I'll add some more info after I use it in at least one game.

UPDATE:
Used it yesterday in a game at GZ. Put about 5 magazines through it before even bringing it on the field.
The pistol grip got a little warm, but I think that was due to the fact that I had a M120 spring in it.
I was using a 9.6V mini battery. 380 FPS with .25 and 15 RPS. The battery moves way too much in the handguard.
I need to put some foam in it to secure the battery. I'll also switch to a M110 spring as I think the 120 is a bit too much for the gun. The battery died right before the last game. I didn't open the GB so I can't comment on the durability of the internals.
I'll change the spring today, re-chrono and post the results.

There was a black Masada there and his rifle broke half way through the day. I can't say what did it. I'll ask at the store what they found.

Pics or it didn't happen!

Put the M110 spring in. 350 FPS with .25 and 16 RPS.
I think I'll leave it like this and see how it performs.
Might, and I say might, need a tightbore.

Very easy spring change. You need 4MM and 6MM allen wrenches.

Idk about you man, but the grouping on mine is shitty, for me the tb is a must.