It's a nice comodity, it means I don't have to look around for a 3/16 allen wrench to stip it down. If I am doing a full strip down of everything I may use a wrenh because it's usually in my hand anyway.
The 05 hybrid adds around an inch, the 06 adds 3/4 inch the bloodline "pear" bolt guide adds 1/2 - 3/4 inch the bloodline "bloodworks" (revolver stylee) adds 1 1/2 - 2 inch easy it is fairly big, but I am going from pics on that one as i have never seen one in the flesh.
As for teh technical aspect of the bolt guide it adds a bit of wieght, unlike the rammer which if i remember from my timmmy affects the bolt position???