I haven't ridden a Spyder, I have a 2008 Goldwing Trike and a 2002 HD Roadking Classic. I finally got the HD back on the road this year. I only rode about 1k miles but it was 1k miles more than the previous 5 years.
Riding a reverse trike like a Spyder, which has two car-size tires on the front, is so much safer than riding a conventional trike like a Harley or GW trike, which has a single motorcycle-size tire. The Spyder's design is inherently better: better handling in the corners, decreased stopping distance and better/easier manueverability in tight parking lots. The Spyder has a real reverse gear. It has Dynamic Stability Control and ABS that makes the trike awfully difficult to tip over.
IMHO, the only advantage the HD and Honda has over the Can-Am is a wider dealer network for any scheduled maintenance or should you break down on the road.
I know of MANY HD and GW riders who have bought a Spyder after testing the offerings of their favorite brand and have become converts.