I've been using narga gun and armor many times in mh3u and gen. I missed that ninja bat kitty on mh4u though. I did get to play MH World when one of my friends had me pilot one of his gunner sets. He couldn't use it properly and wanted to see if a purist bowgunner will be able to make the most out of it. I agree that it improves a lot both graphics and gameplay. The only thing I hated is they removed the scope aiming from bowguns, and that's how I aim since 3u. So I had the whole day trying to get used to aiming in 3rd person which was hard for me. Other than that it was a real good experience.
But i'll think i'll go with gen ultimate first. Part of the thing I like about our hunting group is the way we socialize while playing in a cafe. It will be hard to do that if we need to bring a TV and a ps4 with us.