If you already have it, I certainly wouldn't be bashful about using it. EC is IMO some very nice equipment. Don't expect it to do a lot to the sound - it's pretty neutral. If you want a step up and something to offer some incredible value for the money in a pre - look at Klaus' new Candella preamp.
To me, the Candella is the right mix of tube and solid state attributes. It's extended and fast like a good solid state piece, but offers a tiny bit of warmth and excellent 3D soundstaging like a good tube piece.
Bryan