I soloed it on all 6 of my wizards. I can't speak for since I never did it with that, but I didn't have much trouble on any of my wizards except probably my first time through. But that's really just normal learning curve.
The only trouble I had with this tower was on my storm, but she was only level 25, not really high enough to try to solo the place. The new Team Up option makes it easier to find people to run through this with. The first time I soloed on my Balance, I bought a health elixir, and that helped out a bunch.