"I'm going to give a long and honest review of this gun.
First thing to note, this gun is great for two types of people:
1. People who are veteran airsofters and know the ins and outs of guns.
2. People who know they're interested in airsoft and are willing to spend money on it.
I've broken this review up into the following parts:
1. Performance: Out of the box, mine shot ~350ft/s. It was very accurate for a stock gun, had a decent range (~200ft) effectively, and had a modest rof (~850 shots/min).
2. Internals: I've never had any problems with much of the stock internals. You can't really go wrong with steel gears, solid metal bushings, stock polycarb piston, as you'd expect, and a non-ported steel cylinder. The only problem I had was that one of the gearbox screw holes, where the motor goes, stripped on me. It wasn't a huge deal since the motor is and grip are connected to the gun by the body, and not those screws. However since this was my first real gun, it may have been my fault. The barrel is steel (6.04mm) and mine didn't rattle around at all, especially, after a bit of Teflon tape between joints.
I, personally believe, the barrel is pretty much perfect. The reason is because extremely tight-bore barrels actually decrease the accuracy of your gun. In fact, the most accurate airsoft barrels are the 6.03mm steel or brass ones, not the custom made 5.98mm. When a barrel is too tight, the space between the barrel wall and the bb is reduced. Normally, that space is where the air would seep around the bb. Granted that too much space is bad, 6.04mm and 6.03mm barrels are perfect because that pressure actually centers the bb in the barrel, so it doesn't bounce around inside the tube nearly as much as if there was no air leak. If you want a 6.03mm, you're essentially paying $30 for an inch tighter group at 100ft. not worth it.
Which brings us to the compression features. The air seal is mediocre,the spring is probably around M110, and the spring guide is all metal, but no bearings. If you plan on never disassembling your gun AT ALL until it breaks, then the hopup will do just fine. However, If you plan on teching your gun, a new hopup chamber and loading nozzle is THE FIRST THING you should buy. They suck, and you should avoid messing with them if AT ALL POSSIBLE, because the c-clip is brittle and the only ones available are the stock ones. Also another thing to note is that the ambi-selector switch is a pain to work around, and even more of a pain to install another one. Even worse, its actually pretty fragile, so be careful. It's another of those things you should try not to mess with.
3. Externals: I can't say enough good things here. TRULY high quality externals. if they get shot point blank with ANY airsoft gun, they'll be fine. Seriously, go run and tell Nokia that its got a match in external durability. Battery space is alright, actually, if you're crafty, you can make most fit quite snugly too.
4. Accessories: one thing I love about the Masada is that it's soo easily customizable. That's the way it's designed, to take a new barrel or stock, any time, quickly. EVERYTHING is ambidextrous which is great. The only things I have to complain are that the mag that comes with it is absolute garbage, and many parts are proprietary. The mag will feed reliably for the first two or three fills, then it becomes really sketchy.
5. Overview: the masada is a unique project gun for the experienced, and an awesome beginner gun for the dedicated noob.
Personally, I'd take the A&K masada over the PTS any day, because it's cheaper and will serve you almost as well stock as the $100-more-expensive-competitor will. The PTS just may last longer. When this masada does break, it's a sign that you are dedicated enough to airsoft that it's worth learning the insides of your gun.
The A&K masada is also easier to upgrade than the PTS, and if you know or are willing to learn how to upgrade it, then it can be much better than ANY stock gun on the market. It's perfect for a DMR, perfect for a High-speed AEG.
CQB or Feild, you name it! The world's possibilities are open to you if you want them. You just have to want them, and understand that the "perfect gun" is a labor-filled process.
6. So should you buy this gun?: Long answer short, depends. Long answer long, you have to ask yourself more questions. Are you new to airsoft? Are you sure you'll like it? Do you like teching guns (and can you)? Do you want a unique gun with familiar internals or will a G&G M4 do fine? Are you really willing to spend this much? These questions should help you decide.
I feel that if you are paying just for the machine, then the gun is $50-70 overpriced, but if you know how to work with your gun, and are paying for it's potential, it's upgradeablility, it's awesome looks, and you're willing to make this beauty perform even better than it's looks, then PLEASE DO BUY THIS GUN. I guarantee you that the airsoft community is excited to see what destiny you've planned for it."