I spent the last few months trying different routers, ideas, and antennas.
I’ve found what I feel is the best combo yet.
TP Link TL-WR741ND with a directional antenna.
The AirPort routers distance wasn’t the greatest, and once you start getting low signal your Qu-app refresh rate drops, and airplay starts to drop as well.
300N routers use two antenna’s which makes it a pain to use directional.
MIMO routers use even more antenna’s, even more difficult to direct a signal.
150N routers provide enough bandwidth for a good refresh rate of the Qu-apps, with only 1 antenna.
99.9% of 150N routers have internal, or fixed external antenna’s, so you can’t use a directional = No Good!
The TL-WR741ND is the ONLY 150N router with a detachable antenna I could find, and it runs great.
I’ve been using a DLink directional antenna that has small magnets on the bottom. For indoor use, I just stick it to the top of the Qu and point it at the middle of the ceiling, so it will bounce easily to stage.
For outdoor use, I just mount it at the top of FoH tents point at the stage, and even at 150FT it still works well.
My search is over, seems like this will be sticking with me for a long time.
It cost me about $50 total, both router and antenna.
Sharing for the rest of the people here, the search is over (IMHO)