I shoot with the Cambo Wide DS, 24, 35, 47 and 72XL lenses. I like this camera a lot. I have plenty of friends with the Alpa and its a wonderful camera too. Personally I think that the 'aura' of the Alpa has a lot to do with why people like it.
The Cambo is lightweight, despite its size. I have used it handheld successfully on a number of occasions. The 'bull bars' on the front make it easy to put the camera down on a surface safely... very handy.
I chose to buy small voightlander viewfinders as these generally have a more rectilinear field of view than the Cambo one. I only use these to point the camera in the right direction then use 'polaroids' to finalise the shoot angle.
If I was doing interiors only I'd buy the 47. For architecture generally the 35. The 24 is a 'get out of jail free' lens for tough spots, but the 35 can cope in many situations when you also add in the stitching potential.
The only caveat I have is that the build quality is sometimes lacking. I know people who have had poor lenses, or perhaps I should say 'poorly mounted lenses'. Make sure you quickly perform tough technical tests on any lenses you buy and send it back for adjustment if its not up to spec. I have a sloppily fitting 47XL, but its pin sharp so I don't worry about it. If something like that bothers you, get the Alpa.
I've seen the new compact version of the camera and I think it looks very good though I didn't get a chance to hold it. It has sufficient movement for current MF backs and lenses. I think only my 72L has a big enough image circle to tax its movements while with the 47 and 35 its well matched.
Also consider ease of renting spares (if possible) and the level of support for any platform. Alpa would probably parachute in a guy in a black balaclava if you had a problem, whereas I get the feeling you could wait a long time if there was a fault with a Silvestri. A week after getting my 24XL I dropped it from 6 feet onto concrete and bent the mount out of shape, it looked like a banana. I sent it back to Rene Rook at Cambo and they had it fixed and back in my hands in about 3 days, for a fee of 200 euros. Fantastic.
So a lot to consider... but something like this is an investment its important not to underpay to get what you want.