So far (20 or so exposures) I find the 45 works well. 30 would be a specialty lens for me. If the Xpan will be a keeper the 90 will be a must though.

I can imagine that vertical shots are tougher, because with 'ordinary' composition you need to tilt the camera upwards quite a bit if you do not want to photograph the tips of your shoes (I am exaggerating a bit here) and once you do that you may get a very strong inclination of vertical lines. In my eyes the vertical panoramic format tends to look "thinner' than horizontal for whatever reason ...