The make up of the Sontec MEP-250A is straight forward, but like with any new piece of gear it will take a minute to get fully get it. Each of the two channels gives you three bandpass filters and both a high and low shelf. You've got full control over frequency, Q, and gain on the bandpass filters and just that minus a specific Q on the shelves. I've never seen a manual for the MEP-250A, but if you're familiar with parametric EQ's, you're most likely not going to need any help here.
The sound of the Sontec MEP-250A is really very good. It's not quite like the GML, which I think is way cleaner and more exacting, but I can see where the comparsions come up in terms of it's general make up and what it can do for you EQ wise. To me this seems to color the sound a little bit more, where the GML is totally precise. This isn't a bad thing for the MEP-250A, it's just a different sound and should be treated accordingly. I really like the sound of this EQ and think it can do it a lot for you in a lot of situations.
Simply put, the Sontec MEP-250A is a superb, top of the line stereo equalizer. In my opinion it's still not a replacement for a GML 8200 which is the king of precise parametric EQ, but it's still really cool and worth the time to check out. It will also only cost you about half of what the GML will, although it's much more hard to find since it's vintage and there is no support. Still, the Sontec MEP-250A is a very very good stereo EQ!