Generally I think CVS client in IDEA (4.5.3) is great, though only Import Project annoyed me a bit.
First, I don't see the way how to specify Ignored files before importing the project. I can only see how to exclude some folders, thus being able to mark them as "ignored" later, but I need the way how to specify files beside folders (common thing is to avoid placing IDEA project files - .jpr, .jws.. into CVS repository, since it is not supose to have IDE-specific files).
And second thing is quite unique to my company, but we have a policy to name CVS project with "." in it, which IDEA doesn't allow, although WinCVS and bunch of other CVS clients allow that.
BTW, congratuations, IDEA is by far best java IDE around.