I love that they keep track of who and what I've search for in the past. However, I agree with you that it would be more useful if the My Categories & Companies had a filter for those companies I've used and rated well in the past. I've got a bunch of companies showing up under My Companies which I would either never use again, or have only looked at once and didn't consider worthy of my business. Would be nice if I could bookmark companies I'm interested in, and just have those show up in My Companies list.
Anyhoo, that's my 2 cents for what it's worth....