From my experience with the admittedly few Leica owners I know in real life, they're often awfully desperate to justify their purchase and so are incredibly biased in their appraisal of Leica images. While I'm clearly biased against them, I'd say even I would be a more reliable opinion on the quality of Leica equipment than many of the Leica owners I know. I've presented a shot from my 5D and 50 1.4 with tweaked EXIF to show M9 and Summilux and they were adamant that there was something in the image that Canikon etc. just couldn't match, before I told them it was a Canon image.
I'll admit the S2 is a stunning camera and a beautiful system, and in its usage (studio and landscape) the lack of autofocus isn't a drawback at all and the lenses are stunning. The M system I just don't see it, though. The lens quality in particular I find dubious. I've been through Leica files and not been blown away by the M cameras, and say the 50 1.4 Summilux. That's meant to be the best 50 ever, and that reaches LPWH 2150 in Photozone's test at an absolute maximum. The Canon 135L hits 3300 wide open. I can't standardise those results, and I can't use manufacturer MTF charts because as far as I can tell, Leica only provides MTF charts to show sharpness fallof as a % of maximum centre sharpness, rather than any raw figures.
In film days, yes Leica lenses were very contrasty which was nice. But now that every man and his dog at the very least has GIMP, that's a very strained advantage to claim it's worth the markup.
First of all, the Leica S2 actually has autofocus so it's even more stunning. Such a well designed camera too.
Secondly, looking at the Photozone tests... You're making an extremely flawed comparison, and one as equally deceptive as your EXIF switching. You'd want to compare the 50/1.4 ASPH, which has quite a reputation. But 50mm and 135mm are very different lens designs. Also, you're not even comparing an M lens, but a Summilux-R SLR lens, so that particular 50 from Leica isn't even the same as the other 50 from Leica. You're also comparing different sensor sizes and resolutions, the 50 Summilux-R was on a 8MP 350D, the 135L was on a 21MP 5DmkII - of course they'll post different results. Have a look at the MTF results of the 135 on the 8MP 350D:
http://www.photozone.de/canon-eos/168-canon-ef-135mm-f2-l-usm-lab-test-report--review?start=1
And then look at the Leica 50mm:
http://www.photozone.de/canon-eos/2...pter-on-canon-eos-review--test-report?start=1
The Leica is actually sharper in the corners, worse in center, but much better than the 50L, which is the closest you'll get to like-for-like on a Canon 350D for that site and their test:
http://www.photozone.de/canon-eos/158-canon-ef-50mm-f12-usm-l-test-report--review?start=1
Even so, MTF charts only tell a tiny part of the story of how a lens creates its image and they are subject to so many variables that it's almost pointless to compare them. How about tonal transition, tonal separation, colour balance, blur rendering, highlight and shadow rendering? Leica lenses up until the ASPH days (the 90s) weren't actually that contrasty, they just rendered B&W and colour in their own unique way, and many lens manufacturers who made lenses for Leicas brought their absolute A-game as well: Konica being a notable example, I actually liked their 35/2 UC-Hexanon so much I sold my 35 Summicron and pocketed the difference. So I'm not a Leica apologist - I shoot all kinds of systems, DSLRs, TLRs, RFs, point and shoots and CSCs. I actually hate the boutique direction they've now taken, I hate how dentists have driven up prices for real photographers, but I can't deny they still make some damn fine lenses and cameras.
I just remembered another photographer who uses also RFs in fashion/'serious' portraiture - Norman Jean Roy. Shoots for Vogue and Vanity Fair, uses a Mamiya 7II. Anyway, like atticus said - happy shooting. All these cameras and lenses are awesome anyway, it's all down to how you see and shoot that makes one better than the other.