"I have an RB67 and a Pentax 67II. I much prefer the latter for normal use as it's faster to use and has faster shutter speeds."
The Pentax might be quicker than the RB for normal use but I honestly reckon that the RZ is quicker than either of them.
There have been occasions when I've had to get through a lot of shots in a very brief period of time and the RZ really shines here. Think about the positioning of the shutter release and the speedy wind on action that cocks the shutter and winds the roll on- it's really quick for medium format, IMHO.
Of course, the Rollei 6000 series is probably the quickest MF camera of the lot but it is only a square
In terms of shutter speeds, I don't know what the fastest setting is on the Pentax but is it strictly necessary for portraits? 1/400th is more than
adequate, surely? I thought would have the slow synch speed of 1/30th, on the Pentax, would be more restricting.
It is, of course, a matter of taste...