That will be easier to pick up on.
Rapidly (with much rapidness

If performing multiple F3 / ESC combinations is rapid succession (like when trying to figure out the delays I'm seeing), there will be a point where F3 will not "register" for two to three clicks.
F3 ESC F3 ESC F3 ESC F3 ESC F3 ESC F3 ESC F3 ESC F3 ESC ...
This is observable in both SS 2.0 & 2.5.
Other wildly bantered ideas, maybe even related (?) can be found in this thread, Problem: Delayed View and Delete Operations.
This is observable on both my new & old systems (described in the link above).