If you want to rent a tablet, you'll need to be on the 737 since they have no space for tablets on the E175....other than that, in Y, I doubt it's too much different although if you're traveling with a companion, the E175 has the two seats together which is nice, but if solo, you're almost guaranteed to not have an empty middle next to you since there are no middles. If I were in F, hands-down it would be the 737 for the tablet and full meal service (due to space constraints, the meal service is somewhat abbreviated on the E175).