Here at work, I also have to deal with recurrant unresponsivenesses for quite some time, other collegues as well.
When it happens, browsing with Explorer works just fine, so is that problem very likely to have something to do with shell extensions in these cases? I mean the shell extensions are loaded and working for Explorer just fine it seems. Anyway, I disabled basically all non-microsoft shell and context menu extensions for now.
I also disconnected all mapped/network drives (using UNC only anyway) and also disabled smart favourites and recent listings in DO.
I can tell: That helped. Did not notice unresponsiveness during the last days. Will re-enable different things over the following weeks to hopefully find the real cause of this. The delays and "hangs" have been a real pita recently and seemed to occur increasingly.