(For anyone unaware, a G by a Monster Hunter game means it's had an expansion pack of sorts applied to it)
Monster Hunter 3 Ultimate is, content wise, a direct port of Monster Hunter 3G, which has been out on the 3DS for a fair spell. It's a solid port though, I mean 1080p (wish they'd have locked the FPS to 30, though), online play, can't complain especially if you're a series fan and own a Wii U. If you mean against vanilla 3 though, then yeah, it's an expansion pack. Kind of a meek one though if you're not a Nintendo-come-lately fan, since most of what they did is add back in the content they removed in the first place trying to "reboot" the series which blew up in their faces.
I've a bit burnt out with Monster Hunter currently, though, so I think I'll just wait for a price drop. They've kinda dumbed it down too much with recent entries and in general I always felt 3 was a big step back from 2G, and I don't think 3G will fix it. 4 is what I'm really waiting on, looks like the shot in the arm the series very much needs, as opposed to 3's revisions, which were mostly gutting the content and weapons and adding lousy water combat.
Do not understand some of the things you said , but have played the mh tri on the wii first then the psp entrys. I love tri more (and this is the enchanced port of it). So im guessing ill be happy and in love with mh ultimate