Wind-Ups is a fancy GXB/FXE loader with some embedded programs. Some consider it firmware in itself, so I will not argue that point.
However, "Wind-Ups or GP32" is not a valid decision - you need your GP32 to use Wind-Ups! So I edited your poll to read "Default GP32 Firmware", I hope you don't mind.
I voted "Default", since that's all I need right now.