.net 3.5 client profile

The concept of the .NET Framework 3.5 Client Profile sounds great to me - from what Microsoft say it looks like a target PC can install all that is required to run a winforms, console, or WPF app with just a 28 MB download (rather than the couple of hundred MB that is required for the full framework). All you need to do to make your app work with it is tick the box in the compile options that says Client Subset Only or something like that.

So I was just wondering if anyone is using this new feature (think its new to 3.5 SP1) and if you have any problems with it?