Rodrigue, I've been following your work with the XVario on various forums, as well as on your blog and am not surprised at all by Leica Camera AG's running a story about your and your experiences - and photos. I really enjoyed the piece and, as always, your pictures - of course!
Everything I see from the XVario makes me think it may just be the idea travel camera. Sure, I would prefer a 24-50 f/2.8, but its likely they wouldn't be able to match the IQ with a faster lens even of reduced zoom range.
I just got back from a trip to Europe where I used both a Canon 6D and 24-105 f/4 and a Sony RX100 m2. The Canon with its 24mm end and outstanding high-ISO was exceptionally versatile, but damn that thing got heavy by the end of the day. If I had it to do again, I'd probably have bought an M9 and brought it with the 24/3.8 Elmar and 50/2 Summircon, kept the RX100 in a pocket and still been significantly lighter than just the 6D and its zoom. An XVario would also make a suitable 6D replacement, though I did find myself shooting architecture mostly at 24mm.