One needs to look at this from the reality of BRP. They will A) build what they are capable of building at a profit, and B) build a unit that overcomes buyers objections.
This is why the slower than expected popularity of the F3 is somewhat of a mystery. BRP surveyed and asked those who were not buying a Spyder why not, what would need to change to do so, what their objections were, and the F3 really did address the majority of those objections. It should be a home run, but has not yet hit that status. Bikers wanted to see the engine, get rid of the plastic, to sit with their feet out in front of them, project a muscular image that looked less like a snowmobile or watercraft, have it feel more stable and less like you were going to fall off going around a corner. The F3 does all that.
What can BRP build at a profit? The 900 ACE engine now used in sleds and Spark watercraft would be easy, 90 HP, wide torque band, easy on fuel, lower cost.......but is this something that people would buy? Is cost truly an objection to buying a Spyder? Is it riding position? Is it the image it projects? Is it the way it feels, handles, and rides? Is it DQR (durability, quality, reliability)?
We all own Spyders so we are not really the ones to chime in on this. BRP needs to know how to sell Spyders to those owning 2-wheel bikes, or those considering buying a 2-wheel bike. Will the majority of Spyder owners be former 2-wheel riders, or will they be people who like the thought of 2-wheels but dislike the safety of them? These are the tough questions when you change the paradigm of what is the norm and introduce something so different. Nobody really knows what they want......maybe there is no single silver bullet, just a bunch of smaller nuggets to be found?
The fact of the matter is the RT line is the biggest seller by a long ways. Appeals to an aging demographic with plenty of disposable income. New models are a calculated risk, a new RT is always going to sell. So, how many years between new versions? 3-4-5? Last new one was how long ago?