Pablosbrain: i haven't noticed slowdowns in my crappy 500mhz PoS (Piece of Shiznit) computer.
Timothy: but when Blender is getting bigger and bigger in filesize, using UPX is a good idea for keeping it compact.
Maybe this sounded like a bad idea for most of you, so i'll just keep using UPX myself.
There, end of discussion.
(and again, no harsh comments, etc

)
<edit> BTW, did you read this?
http://upx.sourceforge.net/#overview <edit>
Yet again, no flames, harsh comments, of throwing of files made with other 3D apps
