I'm running Windows 7 under Bootcamp on a 13" MacBook Pro w/Retina. The frustrating problem is with the keyboard and trackpad. They keyboard seems to cause the cursor to jump around unpredictably. For example, filling out a form on a web page could cause the cursor to suddenly jump to a different field, even in the middle of filling out one of the fields. Even using Outlook or Word, I could be typing text in the body and then suddenly find my cursor is up in the font size field. I'm not sure if it's a character combination that's causing this issue, as it seems to be random. All I know is that it makes typing an adventure on frustration.
The Trackpad just seems to lack fluiding. The cursor will suddenly appear to "stick" in some places. If I try to hit the "X" to close an application, it may stick on one side or jump to the other. It's difficult to be precise using the Trackpad. If I use the Magic Mouse, then the cursor is quite smooth. The Trackpad just doesn't flow very well.