It's been commented before about 4x4 vs Prerunner can sometimes just be about "testosterone"
A similar comparison can be made about the i4 vs the v6.
Either engine is "good" and either will be reliable for you, and as said, will not differentiate much with gas mileage - with a couple exceptions. (when needing to really "push" it the i4 will be full throttle, where the v6's torque won't need as much throttle)
But really, it's just about beating's one chest.
The 4 cyl will have less torque and be, as some might say, "gutless" compared to the v6. But it is not to say it's powerless. Several people above have explained they're perfectly happy with their 2.4's and 2.7's...
I come, myself, from having driven one 2wd 22R, two 2wd 22RE's and then a 4x4 22RE. When I test drove my 4x4 v6, I fell in love with the "comfortable power" it had. The off-the-bat torque is enjoyable when you're pushing it or when you're presented with the need for quick acceleration, like a short freeway on ramp or passing grandma's sedan.
If you want something that's a bit meatier, v6. But the i4 will do you fine, and be faithful as a horse. Sometimes I wish I'd gone with a 4 cyl 2wd, but I still love my truck.