We have never made it to Tusker House yet, but I hear that it is really good.
I enjoy both Ohana and 1900 PF just about equally.
To choose, I think it depends on which characters you prefer. We like both lineups.
Ohana (Mickey, Pluto, Lilo, Stitch)
1900 PF (Pooh, Tigger, Mary P, Alice, Mad Hatter)
Also, Ohana is family style table service (you are served, but the menu is more limited) where 1900 PF is buffet. That really doesn't matter much to me, but some people have a preference.
Overall, it is a toss up for me.