BEST is probably the better warranty to get on a Spyder as it/they are partnered with BRP. BEST isn't just about bringing your warranty to 5 years, but also adds towing for the full five year term if you buy the full 5 years of warranty.
When I bought BEST I compared against AAA, and found that AAA on the bike was going to be expensive (RV coverage) and over the term of the BEST warranty and towing, was going to cost near the same... So BEST was the better solution from a financial perspective.
I tend to pay off my vehicles and keep them a long time. I do not typically get extended warranties on my cars or trucks even though I keep them ten + years. The Spyder however was different, and I expected more repairs due to the nature of the machine and the beating it takes. I will not keep my Spyder for ten years, but will for the full warranty term and maybe a year or two at most after.
There is a spyder owner on FaceBook right now that bought a 2008 used in 2011 that was already out of warranty and has a bad VCM or DPS... Dealer he bought from quoted him $1800 parts and labor. He can't afford the repair. Who's fault is it? BRP? The Dealer? or the owner for not buying some sort of maintenance/warranty package if one was offered like they sometimes are on a used vehicle? In the end, it is his responsibility. If you can't afford long term ownership, you probably shouldn't have bought it. I hate to say that as we all love to ride and love our spyders and the friendships it has brought us.
I digress... BEST warranty is probably the best option given that is the one BRP pimps... Probably less likely to give you any hassles and at least you can escalate to BRP who may help you. Any other warranty provider will just be ignored by them.