Search there are a lot of topics on this, some useful some not.
In short I'll summarize it for you:
-if you plan on keeping your truck past 200k the 5.0 might pay itself of if the eco has problems with its turbos, same goes for the resale value, if the turbo's go no one will pay much for the truck
-the 5.0 won't necessarily eat more fuel then the eco if you drive it properly
If you are asking is the 5.0 better then the eco I say no. I say get the ecoboost even ford plans to drop the v8 in the f150 eventually, its just a better engine. It has more power it should last way past 300k.
The only people disliking the 5.0 are the ones that dislike new tech like the turbo's and are stubborn as hell and not wanting to loose the v8 sound which from experience in my 5.4 doesn't even sound good and you can barley hear it anyways. Sticking a loud muffler on it just makes it obnoxious and noisy which is something I DON'T want from my truck. Not to mention I actually give a **** about the people around me and don't want to ride the streets with a noisy exhaust irritating others.
Depends what you want from a truck. Is it for work, or for fun. Both engines are reliable and are quality products.