First of all, I don't see what all the fuss is about with the Leica. It's just a digital version of the R series with a large sensor (hence the S-series lenses). Hoo-ra. Having shot some of the later R-series film cameras, I can attest that they are great. The lenses are top quality. The handling is great. Maybe the S2 has a built-in flash meter, too (I haven't bothered to look that up). However, I think there are a lot of drawbacks compared to MF digital systems.
1) The S system is not modular with respect to the digital component.
2) The lenses are bound to be far more expensive than what you could find for other solid MF digital systems (Mamiya comes to mind in particular).
3) The flash sync is dependent upon the shutter curtain. I've never known Leica to make a leaf-shutter lens.
As for Hassy, they're top-notch systems with some serious drawbacks. To begin, their backs aren't nearly as user friendly as P1 or Leaf. And while you may be able to get a good deal on a body plus 80mm lens or whatever, you'll pay dearly as soon as you want a second lens. In fact, every one of their accessories are horrifically expensive.
I think the real deal in MF digital right now is Mamiya. Their prices keep dropping and dropping. You can even buy a ZD for $5K now (on
KEH).
Also, MF digital does put 35mm digital to shame. One only need to look at sensor and pixel size, and real images I might add, to see that.
Yet MF digital is a VERY big step, primarily because of the digital component. There are several reasons one might NEED to move up from something like a D3X. And if you can't honestly say that you fit the description at least in part, then I think it's obvious that you should NOT move up:
1) You have a compelling need to shoot at higher sync speeds than your current camera and strobe combo allows for and therefore need the flexibility of leaf-shutter lenses.
2) You have clients who request more detailed images than you can provide with your current setup.
3) You have a LARGE amount of expendable income that you would like to spend on a new camera system because you've just outfitted a new studio space, bought a set of brand new Broncolor strobes, a Para 220 and a Cumulite, and want to make full use it all.
4) You have a LARGE amount of expendable income and enjoy working with top of the line equipment. You see digital MF as the future and like the flexibility of upgrading the digital back when better ones come out, while making use of a reliable lens system that may or may not have been around since at least the 80's (I mean no sarcasm there. I love the older lenses).