Efilive offers more versatility then any other, wether you want to blow smoke, have a good towing tune, a mileage tune, 80-100-160-290hp you have it all.
Efilive has the dsp2 which allows you to have 2 programs stored in your PCM and you can switch between them on the fly.
Efilive also has a new "TNT" feature coming out soon with the dsp2 that will allow you to have a dash mounted potentiometer that will allow you to add or take away fuel as you are driving.
If you like to play with stuff efilive is a good choice, but if you just want plug and play there are many other options out there.
But a properly built EFI tune will sure make you smile
The best MPG so far is a LLY crew cab with Efilive, short box 4X4 with 6 inch lift and 35" tires that got 19mpg highway.