.net is basically a cross between VB, C++ & Java.
It allows you to throw stuff together, which can be a good or bad thing depending on your attitude. There is also the danger of rapid deceleration in a project ( in contrast writing stuff in C is slow no matter what :-) ).
If find it easier than MFC & C# is nicer than VB. Converting C code into C# isn't too hard either.
Downsides are even bigger installations ( unless you can guarantee everyone has the right version of the runtime ) & performance. Most of my experience with .net has been with Windows CE, on a p4 you might not even notice the speed drop. If you're just form filling and storing in a database then you're going to love it.