I'm not sure did you check out my Flickr Horizont page?
There are two pictures there showing difference in field of view between those two cameras, Horizont and Xpan.
If you take look at:
you will see how much curvature is introduced by rotating Horizont lens. In reality those chairs are in straight perfect line. I was right in middle of them and maybe 2-2.5meters away. So far this one is perfect example I found in all my pictures of this phenomena. Pictures of the straight long walls are also very indicative. But when you picture everything else this phenomena is very nice hidden and I like it a lot.
Nice thing about S3 is that it has 1/30s. I do not care about anything faster than 1/125 but found that I'm using those slower speeds a lot.
Inside film chamber of S3 I tried last year was very rough. After one roll there was a lot of emulsion dust left inside.
If I have time today I will try to find you few more examples of the same scene taken with Horizont and Xpan.
My approach was to fit pictures taken with Xpan in my vision of pictures taken with Horizont. Maybe if you start with Xpan you can be happier and poorer!? But do not mix them!