I'm finishing my summer job where I write graphical software for our baggage scanners. Everything is done in .NET or MFC, with plain C++ for hardware communication (I don't do any of the hardware stuff). I sometimes resorted to Win32 API calls such as SendMessage to improve performance of a form or control. I've had only a year's worth of CS courses (all in C), but I am fascinated by the Win32 API--it is much larger and more powerful than I thought.
Does .NET simply hide all of the "tedious" or ground level work of the Win32 API? Does the final software consume more system resources or perform slower in .NET?