One of my UIs has a problem where it can chug down if you throw too much data at it. The underlying problem is formatting I'm applying to a native LabVIEW multicolumn listbox (MCLB). I'm not aware of any way to get events out of the MCLB when an item is scrolled into view, etc, so the application just blindly applies formatting to the entire list. Not a problem when I wrote the application because the data set was at most bounded to perhaps 1000 rows.
Being in R&D, we're never happy though