It's not just Photoshop.
We have just done a server migration for a design company using 100+ macs. They were using two mac mini's with 16gb Ram i5 500gb ssd connect via thunderbolt to storage arrays to serve the files used by photoshop currently 15Tb. now because apple hates professionals, see current mac pro (bin) and lack of apple server love. We started trying to convince them that the best way to get a stable system was to move to windows. However the amount of kick back because some plugins aren't available and workflows would be too different for the designers that we had to use another approach.
Unless these fully support both AFP and SMB3 all current plugins for photoshop and autoCAD and can manage multitasking, there is no way we could put one out in the field for this company.
However if it's for the person I saw yesterday who justifies his time with pointless meetings and wants to feel important we could definitely sell him one...