I actually considered getting a zx-m when I bought my first camera body. I think about the only features it really needs is better matrix metering, and TTL flash, to be a killer MF body. Essentially, a ZX-5n without autofocus.
I'd say: -I can easily live with just center weighted metering -better brighter larger higher magnification viewfinder -TTL flash, and make that at 1/125 sync, please -metal lens mount.
But every time I start to design my *dream* manual focus camera, I end up with reinventing the LX (albeit with a faster sync speed). ;-)
cheers, caveman