Wow, good stuff. I like hanging out here, the maturity level is generally a little higher.
Confirmation bias is a good point. We're all here because we all like Spyders (at least I have not seen any deliberate "trolling" by non-enthusiasts).
In addition to the excellent points raised above, the argument could go on forever because "better handling" is such a vague criteria.
If "better handling" is defined as the minimum time around a dry, clean, race track by professional riders on professionally set up machines, I would put money on a two wheeler over a spyder any day. Not only because of the physical differences but simply because you have thousands of skilled engineers, riders, and mechanics and decades of development going toward making the fastest motorcycle lap times possible.
The Spyder is a niche product that has only existed for less than a decade with less support. And the "nanny" engine management system is fundamentally at odds with absolute performance. The nanny is designed to keep you "stable" and will gladly cut power and apply brakes to help you achieve that goal.
If "better handling" is defined as keeping an average rider from impacting the pavement and other vehicles and objects in real world riding conditions (rain, debris, stupid cagers, animals, off-camber roads, etc), then I would bet on the Spyder hands down.
- You can apply maximum braking without destabilizing the platform. In a motorcycle, the harder you brake, the less you can steer. Motorcycles have a "traction budget" that you have to allocate between steering and braking.
- Hard braking on a motorcycle changes its handling characteristics more drastically. If an obstacle presents itself in mid turn, you have to decide between either aggressive steering or aggressive braking, not both.
- Greater contact patch = more traction
- The Spyder is much less sensitive to road conditions like gravel or "tar snakes" because its contact points with the road are not in line with the direction of travel. If you have ever ridden a motorcycle on a steel grate bridge in the rain or on a road with deep rain grooves, you will know exactly what I mean. There is not much more unsettling than having your motorcycling "walking" in and out of the rain grooves trying to find a stable path.