Hi have post this:
"I think it´s better stay with the Einstein.
In the manual they tell from 1/2.200-1/25.000s for t0.5 time…at the same power the Einstein is much faster and still very quick in recycling and with the Vagabond Mini Lithium battery.
With Vagabond Mini Lithium battery you put the Einstein at 25Ws to get 1/11.000s t0.1 or 1/36.600s t0.5 and around 10fps recycle power were in the Pro-B4 at the same power you only get 1/7.500s t0.1 and 1/25.000s t0.5.
Not to fast as other… to many marketing."
in this video http://www.youtube.com/watch?v=jP2RSnPgLd8 in responce to some of the comments... but after some hours they deleted the message.
Why they do that and insted put a responce
Still shooting 35/120/220mm film