I have an 11, it has been a great phone. I can go about 2 to 2 and a half days between charging it. Took my 11 off the charger Saturday morning (around 7am), went to a football game and tailgated before and after, got home late and then yesterday my day started at 6 am and I went all day and I just now plugged in my 11 to charge about 15 minutes ago (around 11:45am) and still had 5% battery left. And I use this phone a lot. I came from an 8 which died unexpectedly, and my local AT&T store had a few 11's in stock (they were out of Pro's) and I got one and have not looked back. It gets better reception than my 8, and the battery life is phenomenal and that is with WiFi and Bluetooth on all the time and using YouTube a lot. Since getting it I find my self opening the YouTube app more and more, lately been reviewing different types of generators. And even though I do not have the extra camera that the Pro has, the pictures have been outstanding.
I know there are a few differences between the two versions of the 11, but the main two that come to my mind without researching is the extra camera for telephoto and the screen type (OLED vs LCD). I think any version of the 11 you get will be good. They both have the same processor and memory and will last a long time in my opinion.