I've been looking forward to that review, and agree wholeheartedly with most of what you said.
It's stunningly well-engineered, slow, hard work (though choice of tyre makes a big difference, like any three wheeler), great fun at high speed, really gets noticed in traffic and achieves a high level of comfort from the outset.
The mesh seat is an excellent example of the species, though being wide of hip and used to hardshell seats I'm not really a fan. It's worth noting that the useful pocket in the back of the seat isn't as waterproof as it looks.
Having that rear mech low to the ground clogs easily and becomes tedious off-road, though (which can simply mean a leafy cyclepath or a hundred metres across freshly cut grass at a campsite, rather than the sort of silliness you ought to be using an Adventure for), and I'd strongly recommend hub gears in the 20" models for that reason.