Which is better - 90 octane no ethanol or 93 octane 10% ethanol

Yeah ^^^, I'm gonna look for some around here. I can't stand the gas-a-hol. It eats everything rubber in sight.

I have had frightful times with my trimmers, blowers, chain saws etc. My mower is new enough and I believe designed to run on it.

I took some of the crap from a local store here and put about an inch or so of it in a paint can cap on a hot and humid afternoon. I let it sit overnight on my workbench, and when I went to the garage the next day that cap was bone friggin dry, it had evaporated overnight.