Just in case this ever turns up in a search, we have had a trial ride one year on (some of my expectations around cycling with/after a baby were ... optimistic ... and so we made our dutch trip on singles instead).
We had a bimble out at the weekend, one year old in a trailer, and I can report the tandem rides quite nicely. Very smooth rolling and relaxed, the steering felt a bit twitchy up front but that could just be that a couple of days gardening tensing me up and killing my flexibility. (Or the trailer increasing the already long wheel base and pulling the tandem back onto the centre line, causing me to overcompensate - I was definitely more aware of the trailer angle relative to the bike than when on my roadbike).
I don't know that the fit is quite right for me - the reach felt longer than I'd anticipated from the description and standover height. Otherwise it's quite a comfortable ride and ratcheted up a big long hill in the granny without any fuss. Seems a solid and pleasant bike overall (notwithstanding the mudguards which I'm sure would shake apart).
I note Brucie's comments above about potentially flimsy chainsets. I don't think this is the machine to put that kind of power onto - the whole feel is incredibly cruisey. Admittedly, that may change with experience, but I wouldn't let it put me off.
Handles nicely downhill, though we kept speeds down for my partner's sake. V brakes did the job without fuss (though I need to balance the front one - it's a wee bit juddery) and felt a lot more positive than the long arm callipers I'm used to.
Just need to ride it some more - hopefully the summer will last!
General cycling advice ( NOT technical ! )