I have a 07 Ford F150 5.4 that hesitates when dropping into a lower gear. Any ideas in to what might be causing this? It runs great other than this.

Has it always done this, or is it something new?
If it has always done this, it is possible that a reflash of the TCM at the dealership may help.

I am assuming that the trans fluid level is normal and that the trans was serviced at 3 yrs/30k miles, as it should have been. If not, then you have to do these things.