Best router for Airplay

I recently bought Roku Streaming Stick mainly because I want to share videos with my family from the iPhone over the Airplay. It's working, but playback is quite choppy for most videos.

Currently my router is low cost TP-Link Archer C6 v2 with openwrt, but considering buying better router if it may help with streaming performance.

Can you suggest me good router with OpenWrt support for smooth Airplay experience?
I'm looking at Netgear R7800, but it's hard to get so asking here first.

... And you're not tying to stream a 4k clip to a fHD stick, are you?

no more than 1080p

define choppy ... does it freeze, to load more data, or is it just not smooth ?

it does not freeze completely. it's just not smooth (skips frames).

The stick itself supports 4k and Apple Tv streaming works just fine, but airplay is not quite not as smooth. That is why I'm thinking if there is enough bandwidth on the router to handle upstream video from ios device and downstream through the router to the stick.

Some Roku devices can connect to wired ethernet via a USB dongle. If that's practical that would probably be best as it would eliminate the need to transmit the stream from the Archer to the Roku over WiFi, thus freeing bandwidth.

It's not clear a better access point is going to solve your problem without more troubleshooting. How far are the devices from the router? How many walls do the signals have to travel through? Are the devices connecting over 5GHz? What are the max WiFi speeds supported by the devices? Are there other WiFi networks nearby using the same channel(s) as your network?

Streaming stick has no wired option.

The devices including Roku are not very far from the router (1 meter), but there is 1 meter thick wall in between. Moving closer to the router eliminating wall effect with an iPhone helps a bit.
I'm using 5Ghz to connect Roku to the router. Signal is weaker than 2,4Ghz but playback is smoother in my opinion. With an iPhone I tried both 2,4Ghz and 5Ghz and it depends. When the signal strength is better then 5 Ghz is also better for iPhone, but I have to move close to the router. In other case when there is wall 2,4 Ghz is better. Not sure about max WiFi speeds for an iPhone and Roku, but assuming they should be pretty good for both since Roku supporst 4k streaming. There are no other wifi networks.

I also did one experiment streaming video over Airplay from macbook connected over ethernet (roku was still connected over 5Ghz wifi). It was bit better but still choppy.

You sure it's not a screen/media Hz issue?

yes, I'm sure. When I play a movie off the stick (from builtin app) there are no issues.