The XR-1 is more rugged, replacement for the GoBook III (IX-260+). Specs are similar to CF-30 (Core Duo 2 GHz) but with better video (Radeon X300 128MB) http://www.gd-itronix.com/upload/specif ... k_XR-1.pdf
VR-2 has the edge on performance (C2D 2.2GHz T7500) and not quite so bulky or heavy. The VR-2 is more domesticated, made for squad car -to- desktop kind of service. Still a bit rugged but not fully sealed etc. In my mind kinda like a CF-74 business semi-rugged ... http://www.gd-itronix.com/upload/specif ... s/VR-2.pdf
The VR-2 I got had a blister on the lid with built-in BT but no GPS. Inside the blister there was wiring for a GPS, so took the good performing GPS out of a $40 GoBook III and swapped it into the VR-2 with only a little fiddling. Did a post on that a few days ago.
ETA: Been using this cheap Chinese adapter for the GoBooks http://www.ebay.com/itm/330487207544
only $11 they seems to work good and have not burned down the house ... yet ......