For those few of you who rent and/or own (I technically do both since LR comes with CC 2014), and have been creating D750 DNG files to go with your NEF's that we need to keep for this site, here's what I'll be doing directory-by-directory in front of the TV tonight.
Step one: Delete any DNG's that are still in the Catalog but will never see the light of day.
Step two: Import all the D750 NEF files (which I have in the same directory as the DNG's).
Step three: In gallery view mode in the Library module, apply a filter as follows - Choose D750 under Metadata-Camera, plus add a text filter where Filename-Does Not Contain-psd to get just the D750 DNG and NEF files (I don't keep JPEGs in the same directory).
Step four: (with the filter still applied) While still in gallery mode, go thru the NEF files one at a time, deleting them if there is no corresponding DNG file, and applying any Star Color or Flag Attribute that might exist on the DNG file.
Step five: (with the filter still applied) Go to the Develop module and on every NEF file choose Paste Settings from Previous (thank God there's a keyboard shortcut)
Step six: Go back to Gallery view mode in the Library module (keyboard shortcut 'g'), clear the existing filter and add a text filter Filename-Contains-DNG. Select all and delete.
Well I can tell you mine updated automatically last night and I have all current versions at my fingertips...best $$$ spent for me because I couldn't ever afford the PsCS at any point in my life this way I have them all and they are always up to date!!!
I have neglected updating. I think I'm back at 5.3 or something.
I think most of the upgrades in the interim have been mostly adding cameras. 5.7 is the first one I recall seeing recently that seems to have some substantial additional content. I will certainly update my copy to 5.7 at home. I really need to update my copy here at work, still at 4.4, LOL.