@Wimpy After testing with my rpi3 for fews days I can tell the release is awesome !
Big problem : Sound lag with pulseaudio !
I have only the same big problem, I use audiojack for sound with speakers and it is a lot of lag due to pulseaudio.
If I disabled pulseaudio all is good (using alsa) but it is difficult to disable it, unmute alsa and save configuration to next reboot and replace the sound widget in top bar to manage sound.
So is it some way to configure pulseaudio with better performance or remove it and go back to alsa easily ? (I try lubuntu which use alsa and all works great for sound but I prefer mate 
)
Enhancement : Provide a package with flash plugins for Chromium / Firefox
I think we can add a package for flash plugin installation, I explain Raspberry fundation provide it in one package (rpi-chromium) so I can make a script to download the package extract the plugin (libpepperflash.so) copy it to system directory then generate the default config file for chromium to activate it.
But maybe the best is to do some package to do it ?
What do you think about this idea to provide very easy installation of flash plugin ?
Enhancement (but maybe unstable, I need to test more) : Use the chromium-browser version from raspberry pi fundation
Raspberry pi fundation have a patched version of chromium with video acceleration decoding, I installed it on ubuntu mate and it work very well on Youtube 720p and maybe 1080p (I have a less big screen resolution) there is some errors inb console but video acceleration decoding seems to work
It is armv6 version compiled but work, they publish the patch 4 month ago because I ask on github (for the 51 version) I can ask again for the new version (56) maybe we can compile an armv7 version with the patch and provide it to users ? It use video decoding with mmal for h264 videos. (So you need h264ify extention for youtube to force h264 over vp8 or vp9).
Just for fun
I manage to compile mpv with hardware video decoding and windowed and fullscreen support (so straight mpv not only fullscreen).
I read 720p Videos with no framedrop and 1080 with very very few on rpi3.
I use FKMS video driver which provide me opengl output and access to hardware video decoding.
I use SMPlayer frontend and it it a plesure because my rpi desktop looks like a real pc
I must ask some change to mpv team because some options we need are deprecated in the last version (0.24), so I use 0.23.
I think it is too complicated for standard user to provide it (because I think FKMS driver is not too stable for now) but it is a good think for the future
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