They have never appeared in video as they should. Partially because they had great video transfers for their era and the financial crisis MGMUA was perpetually in prevented further work. Indeed you guys are right in that the blus are all a mix of old, new and even Lowry scans without extra tinkering. Why it's such a mess is anyone's guess.
With the Brosnan era none are what they should be. The hdtv airing of the cropped Goldeneye is so grain filled that it is beautiful and finally somewhat like the film I saw all those years ago. It appears they somply reverted to the dated video master done all the way back for the LD which was incredible for the time. TND fares better but is colored differently from the old LD/DVD master and comes off as both flat and cold-not at all like the theatrical. TWINE goes further on this point, with the old DVD/Japan LD having at least a more aesthetically pleasing color palette. DAD looks best but still comes off as a bit videoish in places compared to the prints I saw many times.
These were gorgeous films all shot on the tail end of properly shot and developed scope celluloid and should look staggeringly good. And to be honest the controlling interests care more about flogging copies of the films in endless repackages more than the series preservation. For all the talk about the Lowry work, only 11 wee scanned and all have been mucked with.
Don't even get me started on the audio mixes. All four had pounding aggressive and stylized 5.1 audio that knocked you silly whether it was Dolby DTS or even Dolby stereo. The old LDs and DVDs give you an idea of this but to my ears the BDs just felt all level normalized and without the same immediacy. GE sounds great matrixed, in the hot LFE old mixes but the BD seems flat. TND is just louder in the BD and not like the theatrical which was one of the best iVe ever heard. TWINE I saw in Dolby EX and that was great, very active for a smaller film, the DVD may be the same track and sounds how I remember mostly. DAD for all its faults had an awesome mix in both Dolby ex and DTS es (I saw both). The first DVD has these encoded where the others do not.