Kind of yes, kind of no:

- WinForms applications also took visibly longer to load than Win32. I didn't dread loading them nearly as much as WPF, yes, but I still did. They weren't what I'd call "snappy", but they were... usable enough.

- WinForms also stuttered (in my experience) with the GC. Again, not "snappy" in my experience, but this was more dependent on your use case.

- WinForms were .NET 2.0 rather than .NET 3.0, with fewer modules to load. It certainly felt more lightweight, which from my memory (of how the hard disk behaved) correlated with that.