ultimecea

MH3U is quite a bit more than MH3. The monsters you can fight pretty much doubled if not more so and there is a third monster tier. There is also the addition of quite a few weapons that you couldn't access before. Also there is a little bit added to the main story including a second shakalaka helper, which apparently has humorous interactions with Cha Cha. If it was just a port I wouldn't of bothered.

As for MGQ side stories. I'm kinda feeling lazy about actually finding and adding them in.