I have no XT coverage at home but I do get a whimper of Vodafone GSM. I really like the value offered by compass (25c anytime is just too cheap to pass-up) so will most probably port-in tomorrow but this is the sticky question, people have me set as Bestmate and often send/call me from Motormouth and other on-net offerings.

Additional question, is the voice wholly carried over Vodafone's decent voice circuits or does it plumb back into the Compass system? that could be the make-or-beak.