I also think the Finder interface is just fine because there are so many other ways to navigate around. From the command line of course, spotlight works great as well, and usually files and folders will also be better browsed from the application managing them (e.g.A text editor's file panel, or photo management software, vlc or itunes, etc.)
But, what iritates me is very poor handling of network shares. Those are critical to me, and it just won't work perfectly. On a previous job there was a windows share that could be browsed in command line but Finder wouldn't open the folder.
Or the credentials would get messed up every once in a while, with old values filled in when I logged in with the new credentials so many times already.
Or the Finder would go beachballing and stop responding when an nfs share is disconnected while navigating it in the Finder.
Or the list view refresh on a dropbox share while renaming a file, which can result in a partially typed file name getting commited automatically.
I hated windows, but I have to concede Explorer was rock solid and basically bug free in comparison.