I use to use StaBil. No particular reason why I changed. Now I use StarTron. BEWARE: There are a few different strengths.....How many
ounces per gallon to use. The bottle cost difference can be significant.
My results so far have been positive:..the motor always starts after the winter layup and runs fine during the season. In the boat, which only gets about 15-20 hours of use a season, I always add some with Every Fill Up. It only amounts to an ounce or two per 20 gallons. I carry a "Shot Glass" on the boat to measure it.
One season, I didn't commission the boat at all and it started right up after the two winter layup.
I also use it in my lawn tractor, weed whacker, chain saw..etc.

NB