I don't mind Ryback. In fact I kind of like him, if only because he's a breathe of fresh air. It's nice to have a big named face around who doesn't suck up or spit out shitty jokes all the time, and I imagine that's where a lot of the appeal for the audience comes from too.
However, he hasn't shown himself to be too great in the ring (not that he's been given too much of a chance though) and his mic work is... uh. Yes, the guy does seem to get winded quickly in longer matches. Yes, he does have goofy facial expressions: not nearly as bad as Swagger's mind you, but even so. I'm not sure how much lasting potential he has.
And yes, he was pushed too quickly. You have a few months of squashing jobbers, then straight to the main event? Okay, but now what? Back to squashing jobbers? Heh... no. Unlike Goldberg his squashes matches aren't particularly fun to watch so that's out, and it just seems like such a huge step down to go from feuding with CM Punk to squashing 3MB every week again that the audience will lose interest.
Like I said Ryback is fun to see around right now but I really do think he'll wind up being a fad. I'd be shocked if he's still in a main event position in the company 2 years from now; probably even 1.