I am not swayed in favor of the lepto vaccine given the statistical information about it, which must be weighed against the fact that there are a lot of reactions to the vaccine, especially in toy breeds which are not well quantified. It makes it easy for vets to claim that reactions are "anecdotal" along with the fact that vaccines are still big business for vets. There is almost always going to be a justification for a vaccine, but there may be more than one justification for not giving it all the same. I have personally been on both sides of this having done the lepto vaccine and now no longer doing it.
I had a dog come up positive for one strain of lepto a few years ago and really pondered the decision about vaccination. My vet said this to me, I'm copying and pasting:
We only carry the separate lepto vaccine for 4 serovars. I would be happy to try to reach Dr. (Specialist Name) to discuss further prior to vaccination. I am not a fan of that vaccine unless really needed. We do see more reactions to it.
Here is a consensus statement from the ACVIM on leptospirosis and it has some good info to ponder.
2010 ACVIM Small Animal Consensus Statement on Leptospirosis: Diagnosis, Epidemiology, Treatment, and Prevention