I would choose the Prestige RG1570 over the Xiphos personally. I think that the RG is a more comfortable shape, and the Prestige level hardware and quality control are better than on the Xiphos.
I own a 2006 RG1570 and a VBT-700(the v that was released along side the Xiphos, with the same specs), and even though the VBT is a good intrument, the 1570 is better imho.
Whichever one you choose, enjoy your new axe.
Rock on!