Since the other reviews are...

daveHAWKES, New Zealand4 星
Since the other reviews are about ten years old, let me say that I have been using ConponentOne Studio for Winforms for many years now, and it has become a very mature product. Controls such as Inputpanel can be used to whip up applications just as quick as MS Access apps. The support from their website is very good, and they have Help in all formats including PDF.