One big advantage of a trike that hasn’t been discussed much in this thread is that when you stop, a trike just stops, where a bike will fall over if you don’t do something to prevent it. This appeals to a lot of folks. At very low speeds a trike is extremely easy to control, where a bike isn’t.
With trikes, you have two choices. You can have the single wheel at the front, as in a conventional trike, or you can have the single wheel in the rear, as with the Can Am Spyder. The problem with the single wheel in the front is that it’s not exactly the most stable configuration in a turn, which the British TV show top gear demonstrated very clearly in their segment on the Reliant Robin, a 3 wheeled car with the single wheel very unfortunately placed in the front:
(for those who don’t want to watch it’s basically Jeremy Clarkson flipping a Reliant Robin onto its side every time he goes around a turn over and over and over).
A typical trike isn’t usually quite as bad as a Reliant Robin just because their center of gravity isn’t as high as the Robin’s. But it still suffers from the same basic problem.
Having the two wheels in front, as in the Can Am Spyder, makes the trike much more stable in a sharp and high speed turn. If you look at the design of the Spyder, not only do they put both wheels in front, but they also have the entire thing sit fairly low to keep its center of gravity down low, which also helps with stability in turns. The long and short of it is that the Can Am Spyder will give you all of the benefits of a conventional trike (can stop without falling over, easy to control at low speeds) without a conventional trike’s nasty tendency to want to plant your face into the pavement in a high speed turn.
A Can Am Spyder can’t lean into a turn the way a bike can, so it’s not going to match the performance of a bike. But if you are one of those folks that likes a trike, the Spyder will significantly outperform a conventional trike in a turn.
As I understand it, a Spyder counts as a motorcycle in PA. So with very little training and practice you could take your Spyder in and get your motorcycle license. With the same level of training, most folks wouldn’t be able to control a bike well enough to pass the test just because of the low speed balance issues.
Personally, I’m with NotDeadYet. Ride what you like. No one else has to like it but you.