Does anyone have experience with a tandem trike? Specifically, I am considering purchasing WW TTTandem, GS GTT, or the Organic Engines Troika. Any input would be appreciated.
Thank you.

What part of the country are you in? I am going through the same process now in trying to find the right trike for my wife. From an encounter on a ride last weekend found out about a recumbent shop in State College PA that carries a number of brands/models of trikes -- https://www.rbr.info/ Hoping to take a drive and check them out sometime soon.

I've dealt with Rob @ RBR on the phone. He was very helpful in resolving my problem.

I have only done a few miles on a TTT and found it a good ride, but would not recommend buying anything unless both you and your co-rider have been able to ride at least an hour or two and are both very well satisfied.

George

I own a Greenspeed GTT2s and IMO is the best of the three, not to say that all three are not good trikes. I've rode with a couple who ride the WW and IMO it has a lot of frame flex which I personally do not like in a trike. The Greenspeed has very little and also has a ridged frame, meaning it has no seat adjustments, sizing is all done through the booms. I've never had any experience riding or riding with someone who owns the Troika so I can't really say. Another Trike you may want too look at is the Trice, they also make an excellent trike.
Try looking online at the Hostel Shoppe site, they sell the GTT and the WW and you can compare spec's on the two. I think in the end what it comes down to is how much money your willing to spend.
Another thing to consider with the money you're spending is the resale, you'll always be able to get most of your money back on the GTT or Trice.