>If i have method code which references this.control for several controls (~30x) should a With..EndWith be used? Does it affect performance in any noticeable way?

Yes, using WITH...ENDWITH is faster because otherwise the object references have to be completely resolved each time.

>Does a fully qualified object (thisform.container1.container2.control) access any faster/slower than this.control in the container2 method?
>Should the With be fully qualified? ex: With thisform.container1.container2 vs With This

See Above. The more "dots" the longer it takes to resolve.

>I know it doesn't affect the functionality (they all work) but i'm curious how performance varies with each technique (and don't know how to test it correctly)
>
>any thoughts?