If buying new they are basically same price, V is smaller and more maps etc apparently so I would say get that. Plenty of people on here know all the technical boring stuff though Over to you Arthur........
ok, biggest thing with PCV is up to +250% more fuel up from +100% for improved fueling on 8 injector bikes what that it was ever a problem with PC3 in low state of tune, also one more thottle position up to 10 from 9 with PCV, as you say smaller and can have Map switch without the need of the Hub and Autotune can be added to PCV not supported with PC3 other than that no much they both do the job and you would never know one from the other on a ride, on paper the PCV should be a little smoother but they are only as good as the man mapping it anyway.