Cloudlifter, hands down better. I had one, sold it when I picked up a Millennia Media HV-37, didn't miss it for a while, and of course now I have more than two ribbon microphones, so I wish I hadn't sold it.
While it never did anything cool - to my ears - for any of my condenser microphones, I also used on with moving magnet dynamic microphones, and on some of them it also made a positive difference. The one that benefited the most was an old RE-20.
I didn't sell my SPL Micman, which has some extra gain, so that's what I'm using now, but really, I need to pick up a pair of the Cloudlifters.
BUT... try to find a way to audition both of them if you can, and be the judge - $250 goes a long way