I've only just got UA and was pretty underwhelmed on first listen, but it's growing on me fast (as long as I ignore the lyrics).
Not crazy about Glen Drover - he has some of Chris Poland's legato thing going on, but he's less creative. He seems to slip too easily into shred-w**kery when something melodic would work better.
I take Davey's point about Megadeth being very much Mustaine's band, but some hired guns are better than others, and I think Marty Friedman made a big contribution to the band's sound. So did Max Norman on the albums he produced.
But overall, I like UA a lot - which is great, as there are so few new metal albums I enjoy nowadays.