Thanks all.
I have had a ride of both and both seem fine, different but both are ok. Since I haven't had a bike for many years I don't really have a riding style to compare.
Sounds like the XR1 is the pick of the 2 and I do like the color of the 2015 model.
However a mates son works at a bike shop that sells Trek so he is getting me a price tomorrow. If the discount is great enough then that may sway my opinion. Both retail for the same price here and I doubt anyone will discount the new 2015 a Giant.