As much as it would be cool to own either the P25 or the 1DS Mark II they are the same as the "top of the ad" computer. You pay a premium for the best and the brightest. Then within a couple of years this "best" computer may be so inferior that it doesn't make the ad, never mind staying at the top. Yes the S Mark II and the P25 will still take great photos in 24 months but we're not all drooling over the original 1DS are we?
If I had the money to buy one of these cameras it would be the Canon. The specs are pretty close - at least in that specific review - and I really think that there are other factors besides cost which affect image quality.
When I worked for a daily newspaper I had a guy travel with me on a ride-along. He was on the board of directors - which he told me about twenty times! We were using Tri-X film at the time, which most black and white newspapers were using I should think. Anyway he wandered off to talk to the pressmen one day and came back angry that we weren't using the far superior Plus-X. He (as the pressmen had obviously explained to him seconds before) pointed out the obvious benifits of the finer grain, better tone and so forth. So I explained to him that finer grain and even tone meant nothing if we were forced to use a slow shutterspeed and the image was blurry. So technically he and the pressman were correct, but in practice they were not.
In the review Canon's wide angle zooms are criticized as being inferior, especially to the Contax's prime super wide angles. Yet being able to go from 16mm to 20mm in infinite amounts and without removing a lens, is not taken into account. Being f2.8 isn't taken into account either. It's kind of like saying that the 300 f4 is better at f4 than the 300 f2.8 is at f4. Well it may be true but now put the 300 f4 at 2.8!
I come from Mamiya mediun format with prime lenses and I can't tell you the sense of frustration that I felt when I shot wedding this past summer with the shots that got away.
With Canon's lens line, the difference in cost, and - quite frankly - the fear that there might not be MF bodies to put these things on in a couple of years, it looks like a no brainer to me. Even the current and superior technical specs will be met by Canon then and it's not like the S Mark II will be producing garbage now.
"There's never time to do it right. But there's always time to do it over."
Canon 5D, 50D; 16-35 f2.8L, 24-105 f4L IS, 50 f1.4, 100 f2.8 Macro, 70-200 f2.8L, 300mm f2.8L IS.