Ethanol and octane level for best/safest DD power

[m5james]

I decided last night to find myself an Ethanol-free gas station in my area for a fill up to see if I'd notice the differences. While I've only driven about 20 miles, the biggest differences I can notice is the price as it's about .40 more at this station, making it $3.79 per gallon. I'm going to be running meth soon here due to going with a Stage 3 tune, but I'm wondering if anyone's got factual information about if there's any benefit between running $3.39 E10/91 octane gas from Top Tier stations (even AM/PM Citgo gas is Top Tier and they're everywhere around me north of Seattle) vs $3.79 E free/92 octane gas from a no-name station for daily use. Due to whatever reasons that caused my Index 7 injectors to fail, I've spend about $1100 total to replace them with BMW's latest and greatest Index 12 injectors that are supposedly supposed to handle ethanol better, so I'd like to avoid that swap in the future again.