Go the Anthem O... It is 0.5kg lighter to begin with and the XT shimano kit really is top shelf in terms of performance. I had the SRAM X7 gear on my last Trance and it was good, but actually wore out fairly quickly. I've done 24hr races, 100km marathons on my Anthem and not a hint of a complaint!
Don't be put off by the suspension set up of the Rock Shox, it is not at all difficult to dial in. Infact, it is quite easy. Both the fork and the rear shock have PSI guides for rider weights and the stachions actually have marked gradations to easily measure sag. I put in the recommended PSI for my weight, checked the sag and finely adjusted to suit my preference - haven't touched it since! Smooth