Yes: memory ceiling is huge, WinRM is buggy and unreliable, performance is "variable", totally inconsistent handling of dates and times, being .Net it's UTF-16 internally so streams are painful to work with, escape characters argh, variable scoping is horrible, most of the API you have to hit to get stuff done is wrapping ancient bits of weird win32 and DCOM and WMI thus has inconsistent error handling and ability to actually do what it is told.
I've probably forgotten a few things.