I use a B1 for my monorail. Not sure if that helps you at all as you say you're looking at the B2 (quite an investment!) but I have been happy with mine.
For the record though, I think one of the main reasons I like mine is just that it has the adjustable tension (which I'd imagine most ballheads have, at least the heavier duty ones), it looks nice, and because I use an Arca-Swiss camera, so it's the same brand (I tend to remain loyal to certain companies!) but moreso, my monorail clamps on in place of the quick release but the bigger advantage is I can slide the monorail (couldn't do that with any quick release) which means I can keep the monorail on the tripod and carry the camera in a backpack.
I wish I could comment on the Linhof, but I haven't used or even heard much about it. Personally, if you don't have an Arca-Swiss camera, then I'd recommend going with the cheaper one, unless you think you might always wonder, "what if I went for the Arca, or what if I went for the Linhof."
Just my two cents. Of course, I just started large format a few months ago. Hopefully I was able to provide some sort of valuable information. If not, I'm sure many others out there will!