There isn't much information out there. I agree. I'm going on customer feedback. Many were very leery because these are not listed for the RS or ST models. But the frame geometry is very similar. I suspect that the spring rate, hydraulic valving, etc., may be a bit heavier for the heavier F3 version. But the Fox shocks for the previous models were a bit week (IMHO) anyway. Which seems to be a typical approach by BRP.
The bottom line is. They are at least comparable to the kit you referenced. You're not paying for a virtually worthless sway bar. And I think you will be very happy with them. Everyone else I've recommended these to were well satisfied. For the price. It is a pretty incredible deal.
I don't mean to disparage the BRP 'Upgrade' sway bar that comes in the RS/ST upgrade kit. But believe me. We tested this bar before I ever bothered to make a sway bar kit for these models. Several experienced riders tested the BRP bar on a twisty course and were unable to discern any difference from the stock bar. But, when we swapped out the stock shocks for the Fox, the difference was quite evident.
I try to recommend what I know works. That is what I want to hear when I'm looking for an upgrade and I assume everyone else is the same. Still, it is just one man's opinion and everyone should do their due diligence and come to their own decision as to how they want to proceed.
The Spyder is just so AWESOME when set up correctly.