Terry, looks like you're still undecided uh!
It's best if you make the choice for yourself, opinions are sometimes great, but remember it is you who will eventually be shooting the bow!!!
Like some here, I have all three in the basement. The05' Allegiance, 06' Tribute and 07' Guardian. So far the Allegiance has been the bow that brings home all the bacon.
For me, the Allegiance is a longer bow compared to the Tribute and so feels more stable to me. The Guardian, well let's say I have some issues with the concave riser and two piece grip and some of my shots are moving to the left, an 1" or 2". This is just all in my form, but this bow, because of the grip, doesn't appear as forgiving as the Allegiance.
Takes a bit more concentration, focus as well as form, the Guardian does, but the Allegiance, this bow is all just natural--pick it up and put the arrow where you want to.
I may eventually sell the Guardian, unless of course I can come up with a more comfortable feeling grip. As for speed, well to be honest, the Allegiance arrows hit the target 'louder' than his two siblings. I've cronied them all--using the same arrows and identical bow specs and yes the 06Allegiance arrows are moving a bitfaster.
Tomorrow I'll have my 05' Allegiance in hand the officially open our 2007 Turkey Season! Wish me luck!