I got a couple of the figures. Thus far I've only opened and checked out Iron Man, Captain America, and Wolverine Origins leather jacket logan, and lumberjack logan.
I think both lines have had different designers and thus are not consistent. MU has ball jointed shoulders/biceps but GI Joe style hips (hasbro hips). Wolverine origins has GI Joe/Star Wars arms, but ball jointed hips (ML style).
I can't really say "oh, the sculpts suck". They're a smaller scale and won't be amazing, but the sculpts are pretty good. There's a couple over TERRIBLE faces (yellow/blue wolvy and yellow/brown wolvie, Green Goblin, Punisher). Cap's head is tiny on a larger body. Iron Man is all around solid. But Hasbro also has had some terrible sculpts, terrible paint, and even worse articulation on their 6" stuff. So really, saying if one scale is better than another based on articulation, sculpt, and paint is really pointless. 6" ML have had some major duds and so will MU.
But to collect in this scale or not to collect in the scale? FTB and Spideyboy have been going back and forth like a bitter old married couple. Both scales have their pros and cons and it's going to come down to personal preference. I enjoy the smaller scale to a degree because I mix brands, so Hulk will probably be posed pounding storm troopers while Wolverine battles with cobra troopers. But everyone has their personal reasons and it's rude, idiotic, and just flat stupid to be saying that those reasons are wrong.
It's unfortunate that our beloved 6" scale hasn't been given the treatment it deserves. It's ridiculous for Hasbro to think they can sell us the same characters again but at a different scale (even though Hasbro's main sales technique is to sell the same character over and over again with minor differences). But, we're all going to waste our money in the way we see fit.
So eat it.