Apple TV 3 vs 4 only for Airplay?

[marcolin]

I have this ATV3 that I use in my home office *only* to stream via airplay audio/video to a non-4K TV with a soundbar.
typical use is airplaying Spotify or AppleMusic from an iPad or use TV as 3rd monitor for my iMac (2nd monitor via thunderbolt).

especially in this latest scenario I often experience big lags... do you think I can expect any improvement upgrading to a newer ATV model?
in my understanding newer ATV should have Airplay 2 vs standard Airplay... but is this a thing or the Airplay technology is basically the same and the bottleneck isn't the old ATV? (maybe wifi or my 2017 iMac)

I am not interested in any of the other advantages the new Apple TV may bring, because I will not use them anyway in this setup.
Only Airplay matters to me.

thank in advance for your help!
ciao,
m

 

[Meuti]

I have an ATV 3 connected to an older TV for mostly the same purpose. I can stream music and photos from iPhone or Mac without any issues, but when I'm mirroring a live stream video it lags too much to make it viewable. Streaming the same content on my ATV 4K doesn't lag at all, so I would say it might be an improvement for your needs.