I prefer 2.07.17’s caching system …
Go into “Gallery View” and it caches the Thumbnails … when you change to other views (Large Video, List etc …) the thumbnails are already there instantly … because they have already been cached.
Later Firmwares cache the thumbnails for each and every single view.
ie. If you’ve got 200 movies and choose Gallery View … as you navigate, the Thumbnails cache one by one.
Once you’ve finished and decide to change the view to Large Video Thumbnails the whole caching procedure begins again for that view.
Also later Firmwares when scraping Movie info … automatically downloads backdrops(fanart) for each movie you grab info for (it does this wether or not you want it to)
Firmware 2.07.17 … does not cache backdrop images for movies (it streams them)
When navigating via the remote control, i prefer to press and hold the navigation down and scroll through the movie list one at a time. Which works fine with 2.07.17
Later Firmware … if you do this, within a second or or two it starts jumping thumbnail pages… which personally i find disorientateing and annoying.
A trick “Workaround” fo Metadata for Folders (eg. Plot,Title,Genre) no longer works properly in Later Firmware.
Later Firmware, MPAA tags No Longer work in List View,Video Browse,Large Video Views (they still work with 2.07.17)
Later Firmware, GENRE tag no longer works in Preview View (still works with 2.07.17)
Later Firmware, ARTIST tag no longer works in Album Playback View (still works with 2.07.17)
Later Firmware, Delete or Add a movie with the Media Library “ON” almost seems to recompile the entire Library as the WD blinking LED seems to go forever … Firmware 2.07.17 blinks for several seconds then stops and finishes.
.metathumbs in Later firmware are a pain, 2.07.17, if the internal scraper grabs a thumbnail i dont like … i just simply replace it with a custom one… Firmware 2.07.17 replaces the image within several blinks of the LED light and it’s done.
And yeah, PNG’s for Thumbnails stopped working after Firmware 2.07.17 
P.S. I try all the Latest updates when WD releases them, try to get used them …(or deal with them)
but always end up rolling back to 2.07.17
Online Services dont interest me … which seems to be the major focus of Updates now.
(And attempts at upgrading other features whilst breaking other features/operation is pretty disappointing)