The MOTM-950 can power about 12 "old" MOTM modules AND 8 500/600 series at the same time.
Sorry to belabor this Paul, but (since I forgot to order one with my last order) I'd like to know more specifics. Will the 8 500/600 suck up all the available 5V line? Do you have an average for the current from the 5V line for each 500/600 module? I think you said the 500/600 would use very little of the +15V -15V? If the 950 was used (almost) exclusively for the 500/600 series modules, how many would it power and would it be underutilized on the +15V -15V sides?
I'd prefer not to have a whole bunch of little power supplies in one cabinet, but I remember checking out PSUs a few years ago and I seem to remember that the 5V leg always had way more current than I thought I'd need while the 15V legs didn't have enough.
JB