I agree with Spyd3r. It's the difference between driving and riding, between sitting in or sitting on, between handle bars and a steering wheel. The Slingshot is a modern Morgan Three-Wheeler if you will, although the Morgan is much cooler in my humble opinion (and still available to buy).

There's also a rather significant difference in cargo capacity. The Spyder RT has a front trunk, a rear trunk, and two hard "saddle" bags where as the Slingshot has, well, nothing in the way of storage at all. The Spyder is also designed to tow a trailer, OEM or after market, but I haven't figured out how one could be towed by a Slingshot.

We ran across a traveler in a Slingshot at Mesa Verde, Colorado, last May whose three wheel adventure had begun in Virginia. When I asked where he stowed his luggage he pointed to the passenger seat and foot well. When I asked what he did when it rained, he said he got wet. The only other drawback I can think of is that enough rain will cause the cockpit to fill like a bathtub.

Lastly, when I opened the current issue of Motorcycle Consumer News this afternoon I found two NHTSA recalls notifications pertaining to the Slingshot. #17V357000 concerns brakes, hydraulics, and traction control and pertains to 2015-2017 vehicles, while # 17V158000 concerns steering and pertains to 2017 models.

We own two Spyder RT models and zero Slingshots, although we've sat in the latter. With an artificial hip it's something of a chore to get into and out of the Slingshot. It's much easier to climb aboard and dismount a Spyder. My two cents for what it's worth. Cheers.