for example make opera's cache 400 mb and fill it and then try to enter to it with nautilus or krusader. they are very long, at least sometimes/some cases. mc in terminal is fast enough.
optimise somehow opening such folders with making less features or less graphic decorations and thumbnails of elements in that folders. (for example open like "console" with fixed width font file list.)
or first time (before that is implemented) make there "cancel this process" button if folder is big and opening going to be long.
also gnome commander is slow in such cases.

06:42 :
or let it do not read and compose something with it whole directory let it only compose things that are going to be shown exactly on the viewable part of scrolling window, and when scrolling, read and compute that.
(15:08 gmt: corrected with inserting 'elements in')