I would much rather have PPLNS.  It's the way to go in my opinion.

Suprnova, is a GREAT pool with quick response from support.

You have to allow your shares to build up over several rounds as OCminer said.

EDIT:  

I'm happy to have a thread here on bitcointalk.org for supernova.

I used to be in the CK/Kano Pool thread all the time when I mined bitcoin.  They know how to run a pool as well.  

By the way, they too run PPLNS.