I too thought this arm seemed too good to be true, and shied away from buying one for quite a while. In the end I went for it, and have been using it on my Nottingham Analogue Dais with a VDH Black Beauty for 18 months.
As I expect you know, it's based on The Airtangent arm, which costs around $8000, I believe. The finish on the MG-1 is not as good as the Airtangent, as you would expect, but the airbeam, VTA adjust, and lift mechanism are mechanically good, and I don't believe they are in any practical way inferior.
I did a head to head comparison with an SME V. The SME gave a greater sense of control, and clearer detail. But not a huge amount.
It was after this comparison that I had a close look at the armwand and slider, comparing them to the tapered magnesium job on the SME. The whole thing is made of half a dozen plastic parts which clamp together. I found that the armtube assembly was loose where it joins the slider, likewise the counterweight assembly. Hmm. I superglued the joins in such a way as still to allow disassembly if needed. The whole thing is much more rigid now.
Did it make a difference sonically? Yes indeedy! It's up there with the SME now. Next I'm having an aluminium headshell made to replace the plastic one, hoping that'll step it up again.
The verdict? Sonically, it rivals the best. Once set up (not that hard really) it's a joy to use - very easy to change the tracking force, VTA can be adjusted while a record is playing. IMHO, it really is THE hifi bargain, I can see no reason to buy a different arm. And there's room for very effective tweaking.
What TT do you have by the way?
All the best
Simon