The 24x36 framing feature of the XPan is a rather poor attempt to bring it into "normalcy" I think. Few lens choices, and slow... But it's a great pano camera, so it's my view that the owner should expect to dedicate the camera to pano shots, and that's a sizable monetary committment. I'd be more tempted by one myself, except...
...I already have a 6x7 camera and a 45mm f/4 lens (and a bunch of others). Ignoring the lack of a 30mm lens, all I need to do to emulate an XPan is crop some off the top or bottom or both. I can change proportions at will. And that's actually a rather nice extra flexibility, but only if you're content with using 120/220 film. The XPan is smaller, quieter, and if using 35mm film is important that's a plus too.
Running 35mm in a 120 camera, conversion or not, takes some dedication as well. The camera needs to be unloaded in the dark...