Revoltechs just aren't a great brand. They're usually pretty cheap compared to others though, so you get what you pay for.
There's some nice PVC, non-posable, iM@S figures out there. The older ones aren't so great, but there's some new Beach Queens ones that look pretty good. I believe there's a new Miki one with her in a pink stage outfit too. That being said, they're A LOT more expensive.