Hiya!
TL;DR the thread, but read the first OP.
Pathfinder will give your min/max/optimizer's a LOT to work with. Be prepared to do a LOT of game-work trying to challenge them!
D&D 5e will give your role-players/casuals a LOT to work with. Be prepared to do a LOT more background/story development to keep them involved!
That said...I've found that most of the time when there are mixes of the two strongest game styles (RP'er vs Optimizer), it doesn't work. Either the RP'ers will be annoyed about never getting to do much role-playing, or the min/maxers will be annoyed about how ineffective the RP'ers characters are.
If you have REASONABLE players all around (regardless of preference), then the game doesn't really matter; the optimizer's will find things to optimize and the RP'ers will find things to RP with.
If they are all REASONABLE, it's a good bet to go with the more "meaty" system; the min/maxers will do their thing, but they won't care if the RP'ers don't do any optimizing. (re: Pathfinder)
If you have UNREASONABLE players...well, you have bigger problems than what system to play.
My Suggestion: Go with either and see what happens. If it doesn't work, switch to the other system. They are similar enough in overall "style" that the specifics will all shake out in the end.
OPTIONAL SUGGESTION: Don't even play a D&D game. Go grab some other fantasy RPG you've had your eye on for a while (Runequest, HARP, Dungeon World, Rolemaster, Hackmaster, Dominion Rules, Fantasy AGE, etc). Shake things up a bit! Life is too short to only play one type of RPG!
^_^
Paul L. Ming