I got my GB Pro on Sunday after arranging purchase through Marco at the NW Pinball and Arcade Show which happened last weekend. It received 705 plays throughout the three days of the show, and it was just one of four there (three pre-purchased like mine and one at the Pinball Bulbs booth.) It was incredibly popular, only behind TBL in terms of people waiting to play (and there was only one of those.)
I really, really, really like it and I'm rather sad it'll be on location by Thursday instead of in my living room like it is now, but I know that in a year or two I can bring it back home all paid for. And of course, I always have the keys to the coin door at the arcade... I'm sure I'll need to visit it often to test to make sure it's in working order.