I wouldn't shy away from an 05. It should have the Carbon Links and the rear triangle is plenty stiff even if it does weigh a 1/4lb more...I mean we're talking a 1/4lb here (which to some I know is a lot).
The 100mm or geeze, to stay with the 'Merican theme, 4" of travel makes the bike a little plusher than an 80mm model. However, understand something here, a Racer-X is a true "racing" platform...ie; the suspension is stiff, which makes it climb like a goat and hold corners like it's on rails, but it's no where near as plush as the ML.
As TiEndo and other's mentioned...the 05's I believe came with Progressive 5th Elements, which in the day weren't bad but it's amazing how suspension has evolved in 2 years. So you might want to consider going to a Fox RP3 or 23. Other than that, don't dis an 05!!!