I've been playing with the free versions of RManager and File Manager.
RManager seems to transfer across the network faster than File Manager (subject to objective confirmation), and it displays a thumbnail and "file name" as well as stats when reaching into the camera roll. However, it does not manage its cache/buffer very well: in the process of copying photos/videos to network storage, it buffers each file first - but then fails to release that storage once the upload has completed and starts the next one... until the transfer crashes because the iPad has run out of storage.
File Manager
seems to handle this better (I have not tested it so extensively), but comes with its own problems: the view it offers of the camera roll is limited to thumbnails only, so it is tricky to be sure what one is selecting for transfer. Viewing any particular image file to check what it is clears the tick list. I have read (but not confirmed) that it can't transfer image files from network storage into the into camera roll (RManager can't either, but will transfer into an album).
In summary, I prefer some things about RManager, but from a practicality point of view a I might have to put up with File Manager (unless I can find another app which combines the best features of both).
In fact, it is SO much quicker to transfer by USB cable (using Syncios rather than iTunes), and file names etc are preserved, the only inconveniences being that it has to be tethered by cable and operated from the PC end, but the fact is that 3GB of data was transferred in just a few minutes instead of hours!
I have split off a longer discussion of pros and cons re image archiving to a separate topic
HERE (click).