>Whereas in NET any such code would be at the form level, meaning you wouldn't have to worry about custom methods/properties at various locations in the controls?

The class level code for a subclass? It must exist independent from any form. But instance level code for anything you add to a form... that may be weird... and somehow reminds me of VB6. Not that I've ever done anything serious in VB, but this gets me a deja vu, I was shaking my head the in the same amazement when trying to figure out some of its quirks.