I got pretty into this game today. Right now I'm running a team of Brock Lesnar (R), Dean Ambrose (R), Ricky Steamboat (R), Zack Ryder (SR), and Summer Rae (UC, Pro). It's nice because Lesnar and Ambrose get the 10% bonus as a tag team, and Steamboat and Ryder get the bonus as well. Having a UC for the diva isn't ideal, but I'd say she wins about half the matches I throw her into. Right now I'm in the process of leveling all these guys up to their max, and then I'm going to start swapping them out for other rare cards I have (I've got Big E, Heath Slater, Rusev, Mark Henry, Sgt. Slaughter, Cesaro and Sheamus, so I have options.)
The game is fun because it's super simple and the collecting part is pretty addicting. Every time I get to the prize screen I'm flush with anticipation in hopes of getting another SR, or even just an R diva, or maybe an identical R card to one I have now so I can fuse them together. That said, the game is definitely going to need to expand in game modes if they want to keep people coming back.
I do get the feeling, though, that they have a lot more planned for this game. I'm hoping they keep developing it and keep track of what works and what doesn't so this can become a fuller game, as it sort of feels like a beta right now.