All very helpful guys. He would be commuting from Atherton, Woodside, Portola Valley area and I would say he is indifferent between going out of SJC or SQL. As brought up, SFO can have weather and higher traffic density issues. Though SQL is probably slightly closer than SJC for him, the reason it was ever considered was because the PC-12 operation was based out of there and he was trying it out. In the past with the NetJets, XO, etc. he has always been out of SFO and SJC which does not bother him at all.
The PC-12 operation is certainly biased towards that plane, however, the main pilots are rated in some small jets and mentioned to him that they have been considering adding a jet to their fleet (Looking for an owner willing to buy one and they would accommodate it). It sounds more and more from you guys that, if it isn't an economic stretch to get the second engine, a CJ2/CJ3/Excel/Falcon400/Falcon800 may be the better move?
The Pilatus operation was able to give him a printout showing that based on X hours of personal use, Y hours of charter these are the economics of owning it. Does anyone know a site that can do similar calculations or where that data might be available for these medium sized jets?