SLIGHTLYCONFUZED  By the way, did you upgrade to Snow Leopard or did you do a clean install?  
(Version 2.1)

SLIGHTLYCONFUZED  Then this is an issue separate from Onyx that is occurring with your computer, as Onyx starts instantly without any lag or strange freezing on several of the computers I have Snow Leopard installed on. And if it's only a "few seconds", that's not too bad. =P  
(Version 2.1)

SLIGHTLYCONFUZED  There really needs to be an edit feature on MacUpdate... typos are evil... =[  
(Version 2.1)

SLIGHTLYCONFUZED  Goodness, what's with the influx of angry people on this site lately? You give an honest review and people jump down your throat. Onyx is certainly my favorite maintenance app and I'm thankful that all this hard work from the developer does not come at a price. It's free. And it has saved me from many some bizarre issues I've had on my Mac. Nothing to really complain about.  
(Version 2.1)

SLIGHTLYCONFUZED  Yeah, make sure you uncheck those options in the preferences, or at the very least, press cancel on the first two options that pop up when you first open Onyx.  
(Version 2.1)