Schoeps offer transparency and neutrality, so any pre will work great with them.
What you are trying to record should determine what pre you use with them.
For taping live shows at a distance, something more transparent like the Grace stuff will work the best.
The Oade, Apogee camp is distinctly wamer and they also sound terrific with Schoeps.
That warmth is a bit of a trade off for clarity though, so it just depends on what YOUR ears like.
I would be in the transparent/transparent camp for any taping situation, but if using them in the studio, I would usually take the other tack and run them through a vintage style pre like the API 3124+ or Great River (neve clone) to give them body and fullness they won't quite achieve with the Grace pre. In that case, you are looking for more warmth and the Schoeps are very adaptable to that. I have found that I quite often add top end to the mixes later to open up the sound a bit.
They are on the darker side of the spectrum, so to hear all of that clarity you have to accentuate it a bit sometimes.