I would like to know how long has anyone flown there inspire. Meaning do they fly till the battery gets to a certain limit and then quit as not to have a crash? A friend of mine is very consertative and flys his phantom vision+ till the batteries get to 30% and then calls it quits.

Lipos are best treated when not depleted below 30%. Getting the charge below that depletes the overall battery life. That being said, I believe the Inspire 1 automatically does this for you. The 15-18 min. flight time should be based off of leaving 30%-ish in the batteries.

I bought 4 extra 5700mah batteries (Inspire 1 comes with one  4500mah). I just wouldn't be able to take the wait for the battery to charge after only 1 15 min. flight. My purchase of extra batteries and chargers were calculated so that in theory I could always have a battery charged and ready to go each time the 15 min. ticked by.

Your friend likely has experience with Lipos in the R/C world - The 30% caution is necessary, especially if you don't have an auto-shutoff protection circuit inline when driving.

well I ordered late in the second round and the 5700mah batteries were and are unavailable for me to order so I ordered 1 4500mah unit. I agree that running them all the way down would impact cycle life but I read somewhere in dji manual that they recommend to fully deplete the battery every so many cycles probably to obtain a balance between cells. also odd to me they suggest a 22c to 28c  storage temp which is a bit higher than I would expect. I would like to ask dji to please let us know what is going on with the 5700mah battery and to include a battery care guide. thanks Jerry