I have an AM Broxa and I love it. It works very well, but had a problem with the frame that I fixed myself. The mechbox is metal (mostly, some plastic sliders, but at least the gears and mechbox externals are metal)
If you are mechanically inclined and can service it properly, then it should do you well. If not, go for something better.
FYI- while I like my Broxa and it serves me well, do some reading on these forums if you are serious about quality (I am). While the AM Broxa is a nice starter, and may require some tinkering from time to time I have a passion for quality- so I also have a RealSword AK Model 56 in my collection. Night and Day (but it too requires tinkering, but on a higher level...LOL