During the upgrade process to 8.4.2 from 7.1.7, we have had performance issues.  One of which Pega provided a hot fix specifically for our use case.  Our standard browser up to this point has been IE. After our first go live attempt users reported horrible performance to the extent, we rolled back to 7.1.7.  After further testing we determined that Google Chrome 88 gave the best experience.  Chrome 90 users have a much better experience than IE but less than Chrome 88. 

We now are close to production ready but still see latency issues in parts of the application we where we are bringing back large data sets.  One user has a consistently bad experience on VPN but not on VDA which we initially associated with latency.  This user has a good internet connection and users with similar setups are not having an issue with VPN.  We do use Zscaler as our proxy.

Has anyone else experienced this phenomenon where 2 users with the similar desktop setups, roles in Pega and internet connectivity have completely different performance.  We of course realize that there are lots of variables for which we are methodically eliminating but wanted to ask the community if anyone else experienced a similar issue.