First of all I have to ask how you figure it's any faster having something run from WBStartup as opposed to the user-startup?
My user-startup is mostly filled with Assigns that programs need ie. assign dpaint: dh1:dpaint
To me it's just a lot easier way to keep track of everything. I actually prefer to have as few things as possible in the WB Startup drawer and move them into user-startup to keep everything in one place. It would seem cluttered to me to have all the assigns and programs in the middle of the startup-sequence somewhere.
As doomy would say, "You don't know what you're talking about when it comes to User-Startup!"