I'm beginning to get good results, and Olivier's fake IBL technique helped a lot. It took a lot of trial and error, though. I'm working on an office setup that uses an IBL and two infinites. I'll post a pic when I've sorted out the specular highlights bit.

It's worth bearing in mind that an IBL on its own isn't enough. You need some kind of highlighting to go with it and that can be an infinite or a spotlight.

Mike