Greetings,
I have written a lengthy review of the 2585 Blancpain powered perpetual which includes a flyback chrono on that famous site( with pictures).
Both watches are excellent and I think the GO might be a bit less expensive. The Villeret perpetual is very elegant and quite reasonable given the level of finishing. The GO layout is much less refined but very legible.
Below is a photo of my perpetual. 