Have owned the 150/3.5 N MF, 150/2.8 MF and the 120/4 MF, all used on D800e, and still have the latter two - which will never be parted with. The 120/4 is $%^& stellar for macro, close focus and portrait work (where I normally use it).
I truly wish someone would license the optics for use on Nikon with auto-stopdown as I'd love to be able to use it more commercially. As one poster said, as you get closer to infinity the focus helicoid 'pitch' gets faster and care must be taken not to mis-focus.
The 150/2.8MF is also a knock-out. Both it and the 120 are very, very sharp yet with a great 'look', strong CA control and color tonality. They're loved by alt lens users on hgh-MP SLRs as a result. I can't use them for commercial work 99.99% of time due to manual stop-down, but love them for personal projects where it's not an issue.
The 150 3.5MF is "ok". Not bad, but not stellar. It's faster sister, at least in MF variant, readily bests it, as does the 120 w/o question.
If I were a Phase MFDB owner considering the 3 (based on the assumptions below), I'd readily, w/o hesitation, acquire the 120/4 and/or the 150/2.8 AF - starting with the 120 due to it versatility.
(Assumptions: The 3.5's AF formula = MF version, the 2.8 AF formula => MF variant (The D has a stellar reputation) and (IIRC) the 120/4's formula remains unchanged)