Fairly obviously, I'm in favour of the Streetmachine and relatives. Its only real flaw is its weight, and that's going to be less of an issue once you're carrying some luggage. It carries a massive load beautifully well. The riding position is fairly high up, with some adjustment in the seat angle (I rode mine with the seat fully forward for a bit while teaching someone to ride it earlier today and was shocked by how much higher up I was). Your head height is roughly the same as that of people in normal cars, and you're certainly high enough not to need to worry about flappy orange flags.
You mention tracks and trails. The awesomely good HPVelotechnic suspension is likely to be a major advantage on naff surfaces, and well worth the extra weight.
I'm a big fan of under-seat steering (and the equivalent positions on trikes). Not having to juggle wrist issues against a sore bum is what really does it for me about recumbents, and USS puts the arms in a completely relaxed position that you can happily maintain for hours with no ill effects. It's arguably a bit weird to get used to, but you don't want to be basing your bike choices on what a couple of hours of riding will put right.
As for three wheels vs two, that's worth some real consideration. Two wheels are going to be helpful if you're dealing with rutted unsurfaced roads or stupid bollards with any regularity. They arguably make fitting it on a train a bit easier (though recumbents and trains are likely to be a major headache regardless). Three wheels mean, amongst other things, you're not worried about maintaining a minimum speed on climbs, which I'd regard as a fairly serious advantage. While I find that, with a bit of practice, the Streetmachine is capable of amazing feats of staying balanced at low speeds, getting started on an uphill slope is distinctly nontrivial, especially with a load.