If the Echo 1 AKM is anything at all like my CYMA AKM, which it looks very much to be (pretty much a direct copy from its appearance), it's a very solid gun. It's got great internals, great externals, and it has lasted me through 6 games, no problems worth writing home about. I myself would go for the CYMA AKM, you can find many reviews attesting to it's quality.
I'd choose the CYMA AKM because it's cheaper, just as reliable, more accurate to the real-steel (none of those fake westernized trademarks... bleh), and if that doesn't float your boat, CYMA has many other different AK variants to choose from. When it comes to the lower priced Kalashnikovs, you can't go wrong with CYMA's newer models. D-boys makes great Kalashnikovs as well, they use a much higher steel content though, from what I've heard.
In terms of shooting power, if it's anything like it's older CYMA brother, it shoots anywhere from 450-480. You'll want a new spring with your gun.
Keep in mind this is all my opinion, I've only ever seen this gun hanging on a wall.
