How do you figure? It would be fair to every single miner. It could even use pure PPS. You pick a percentage, X. If you mine a block, you get X% of the block reward less the pool fee. For each share, you get (100-X)% of the PPS rate less the pool fee.

Variance would be precisely as high or as low as you want it to be. Set X to 0 and you get perfect PPS with no variance at all. Set X to 100% and you get the same variance as solo mining. You get to choose exactly how much variance you want.