Well,
Me and my wife looked at all the options out there. We also talked to ellsworth and ventana. So, the first thing that I will say, I would never give ventana a dime. They were very rude to me and tried to make it seem like he was doing me a favor for buying his product. Also, I ordered one and 3 months later he still didn't start on it. I don't know if he was ever planning to. His product is good, but his bussiness manors are horible and he really upset me and my wife.
Ellsworth was very nice and respectful of all my questions. The only down fall that they have is the one size deal. It happens to work for us. Also, the frame was quite a bit ligther then the ventana. I know it is a tandem but why carry the extra weight.
Also, Have to give white bros a thumbs up on their fork. I have been working in shops for 8 years and have yet to run into a company that takes care of there customers like they do. They built me a 150mm tandem fork and shipped it out to me quickly.
Hadley also seems to be a great company. I have been a king fan for years and own several pairs. The Hadley's seem to be the same quility for less money. They do use a different engagement system, and it seems to be working very well.
I tracked down some old 4 piston xt brakes and we have been enjoying them. I wanted to run dual control. So the rest of our parts are xt with race face cranks.
I hope that this helps.