How are you guys handling pagefile sizing estimations these days? We've basically built all of our non-persistent PVS VDAs using 20GB pagefiles (vDisk is set to use RAM with overflow to disk), but out new environment will have significantly more RAM per host.

I usually configure it with a starting value of 8192 and a maximum value equal to the size of the RAM if the server has more than 8GB of RAM. Otherwise, the initial value is half the size of the RAM.

I have just set it to Windows managed. Unless you have restricted storage and are looking to keep from blowing it up, I haven't seen a performance gain with any configuration over another.

I have always had issues with WEM memory optimisation in Windows managed mode.

I stopped using WEM RAM optimization entirely.

Pagefiles haven't been a concern that I've noticed since about 2010

there is definitely a performance impact in leaving it windows managed if it has to expand the pagefile. There's also an impact in having it set manually and it being too small. I normally leave it at 20gb whatever the amount of ram and only go back and change it if it looks like there is excessive paging to disk.