I keep the install files of the software I use in a folder called Installed Software with subfolders - 'Audio Visual', Development'... 'Utilities' etc.
When I access these folders in Explorer it displays the list of files (.exe, msi and zip files) in 1-2 seconds, although takes quite a few more seconds to paint the icons, but that seems to happen in the background, because there is no hour glass and the folder seems to be usable.
But in Opus I have to wait a long time - 15-20 seconds for a folder of forty files - looking at an empty folder with a hourglass before the list is displayed. When it is displayed all the icons are there, and the list is displayed fast. I tried turning off Preferences->File Display Modes->Details->Display icons, this seemed to make these folders a bit faster, i.e. 10-15 seconds, but still not as fast as Explorer's 1-2 seconds for its initial display. But that setting is global, and even if it solved the problem I wouldn't forgo having the icons present in all my other folders - where I actually find them very useful.
This is peculiar to these folders, everywhere else the Opus file list displays are fast But elsewhere the icons displayed are those associated with a file type or they're .ico files referenced by a folder's desktop.ini. So I am guessing this annoyance is because the icons must be extracted from the exe and msi files. Once I've accessed a subfolder, subsequent accesses happen at the normal Opus fast speed - I guess the icons get cached.
Thanks BetterRed