The whole, "I'd like it if it weren't a Weezer album," or, "It's a good album but a terrible Weezer album," thing is kind of dumb (sorry).
If you like it, then like it - it shouldn't matter that it's so different. Consider following AC/DC if you're focused on what a band should and should not be for the sole sake of being focused on what a band should and should not be.
I really didn't like Red at all aside from a few tracks (Pork and Beans, Troublemaker, Miss Sweeney) and to be honest it amazes me that people can say that it's better than Raditude. When Rad came out I heard all this negative stuff about it so I put off getting it until I listened to some on Spotify and was surprised at how good it sounded. When I got the album I was even more surprised - it's excellent! It's so totally tounge in cheek, I just don't think people get that. Lil Wayne and Rivers singing about partying? It's genius!! It has one weak track for me, the last song on the album but even that is not a disaster. I'll take Rad over Green, Red, Maladroit or Make Believe anyday. It's the album Make Believe tried to be for me, a perfect pop album.