The Spyder RT has quickly become North America's most popular trike, but you did not specify whether you desired the trike feature primarily, or if you were looking more for a stable touring platform. Due to the highly sophisticated nature of the Spyder's geometry and electronics, they are more prone to problems, though not necessarily failure. I am about to have my dash cluster replaced on my 2011 Ltd, but the malfunctioning has been a mere inconvenience. Plenty of storage room, good overall fit and finish, good power, and most importantly, the ability to ride without the stress of possible calamity, like losing traction in a curve, dropping your bike at a stoplight, losing your balance due to passenger movement, etc. You can ride in the rain, the snow (within reason) and in most conditions that would make a sane person nervous on 2 wheels.
With that said, there are other equally comfortable touring machines that should be considered if they are easily accessible and easy to get serviced. The obvious choices are the Honda GoldWing, the Harley Ultra-Classic, the Yamaha and Kawasaki tourers, etc. Three other bikes I would seriously recommend are the Victory Cross Country Tour and Vision, and the BMW K1600GTL. I am a big fan of Victory and currently own the 2012 Vision Arlen Ness Edition, and consider the Victory Vision tour to be one of the most comfortable V-Twins on the road. The biggest shortcoming of the bike, besides price, is the lack of storage in the side bags, due to choosing form over function in their design. The bike is a beautiful machine, and an acquired taste, but worth the look. But definitely not enough storage to ride 2-up for weeks without a trailer. The other Victory to consider, the Cross Country Tour, is an equally capable touring bike without the styling compromises of the Vision, though slightly more "Cruiser Like" and traditional, with a contemporary flair, and more storage capacity than any other production 2-wheeler. Extremely comfortable, a very low center of gravity, and Victories are relatively easy to get serviced. And no-one will give you a hard time about riding a Victory (American Made) as it looks like a really cool version of a Harley, just better looking and more reliable!
The BMW GTL is sort of in a class of its own, and should be considered if you are serious about touring. It is the most sophisticated motorcycle in production, and more technologically advanced than any other 2 wheeler. Also one of the most powerful production bikes, comfortable 2-up from 20-120 mph. It rides with the ease of a scooter, and is not nearly as top heavy as it's predecessors (I have owned both) the K1200LT and K1200GT. The cost of servicing a BMW can be daunting, but with any of these bikes, a 5 year warranty should be available, and unless you are a mechanic, it should be mandatory.
I hope this helps. An important note is that the Spyder is definitely not a "one size fits all" kind of bike, and most people need to tweak their riding position to get the most comfort out of their bike. I was very uncomfortable on mine until recently, when I bit the bullet and purchased a seat from Ultimate Seats with backrest, highway pegs from Lamonster, a block-off from Spyderpops, and floorboards from SpyderRT.com. I will most likely get an anti-sway bar once the new one is available from the preferred vendor here, and might still get the upgraded Elka shocks as well. These mods will have set me back approximately $2200 in addition to the factory mods. Much of this is due to my size (5'11" and 280lbs) but I think some of it is just due to a poor, but evolving, design. I think people of average height and weight are more comfortable with stock components, and from personal observation, the Spyder seems to be more comfortable 2 up.
I hope this information helps.