Chiming in!
I've got my B10 just few weeks ago, it is an older one, made in 1995 according to the serial number. What a great instrument I must say!
Mine has dead preamp (but was really cheap so absolutely worth the money), the pickup is wired straight to the jack socket then I go to the outboard Fishman pre, the same I use for my double bass. It sounds pretty damn incredible
One thing I've tried right from the start is putting double bass strings on it. I had one unbranded steel-core set lying around, had to cut them to length; bridge silks go a bit over the bridge saddle, but other than that it worked fine, the bass plays and feels just great!
I mainly play it horisontally like bass guitar. Tried to play vertically but didn't like it for some reason. Double bass feels much more naturally for me than B10 played verically. Tried it with the bow too but fingerbord radius and stand-off from the body is not big enough: it is impossible to dig in well without touching adjacent strings. It can be done as a gimmick once in a gig but not as main technique....