It's kind of nice in that it does a lot of little things like remove some of the stock apps, apply a nice theme with a transparent notification area, etc. But last time I installed Calkulin's ROM it wiped my data which was kind of annoying. Having to reinstall and reconfigure everything is frustrating.
It's nice as a starter kit but I'm now discovering that I'd rather apply a more standard ROM and take care of theming and removing certain stock apps myself.
EDIT: Okay so it doesn't reformat the phone anymore. Might be worth a shot in that case. But right now I have things set up pretty nicely. Just switched from Helix Launcher to Launcher Pro Beta, which is much faster and smoother.