This is all very relative to the albums and who worked on them. So don't take these generalizations as rules. For example Boston's first album is the best sounding album ever in terms of both accuracy, fidelity, tonality, everything imaginable. The only way to improve that album is to go back in time and get the bass extension down to 10hz for the hammonds, which they could not reproduce at the time using what they did. (the records would have skipped and they most definitely used a high-pass on every record that was put on vinyl to stop the bass from making the needle skip. This is not something you can go back and "correct" in a remaster.
I'm just going to break it down to A. vs D. because there is no way to discern the differences otherwise in any real sense that has much meaning:
I'll point out some things though first:
CD technology was terrible before about 1986, but got phenomenal once they discovered that a lower peak value meant truncated bit-depth. Once they figured that out around 86/87 CD's were the ultimate source of accuracy until about 1993. At that time the loudness race began.
This post is going to get way too long, So i'll keep it simple:
The Old
Old Albums using tape have much better compression. Forcing the tape to compress works better than everything else every devised.
They are almost always accurate as they could get them and generally feature a flat f response. Those guys were purists, they believed in accuracy and presenting an album the proper way instead of jacking up the treble (or whatever) because it sounds better superficially, they knew better. These days, i'm not sure they do as much.
Old albums suffer from loss of HF information (which is extremely unimportant by the way except for drums and keyboards. Meaning you need all the f extension you can get, but the equipment does not have to be anywhere close to matching the sensitivity of the dominant f's. Digital will have a much easier time picking up a 16Khz signal. The analogue will pick it up a lot more naturally requiring less manipulation after the fact to sound like how our ears perceive it.
The New
Newer tech is cheaper and is accurate. That is the major problem, everyone thinks they can record their own albums. Nope. Hire a pro. Pros know those critical frequencies and how to make an album pleasing sounding. There are a thousand ways to make a record unpleasant sounding. Almost all of those are very unapparent and won't be noticed unless you really know how to critically listen to music. For example, if the bass is not eq'd correctly it is going to make the song seem slower and the bass will "hit" you late and totally fuck up the album. this is why a lot of "semi-pro" albums lack bass depth.
Another obvious con is that newer tech sacrifices using dedicated hardware to process audio because someone like myself is not going to supplement their almost free recording setup with a ten thousand dollar effects processor or other essential tools of the I/O console. Someone not unlike myself who knows how all the "tricks" are done manually, so sometimes this isn't all that much of an issue.
Newer albums can sound very very muddy is if the lows are not tamed.
Digital albums that are compressed suffer from WAY WAY WAY too much 3-6Khz influence. There is a simple reason why, because that is where our hearing is most sensitive and these f's jaked up sounds louder. Much should have a certain transparency.
Digital is sometimes very very aerodyne (lacking color) or way too colored. This is purely technique. As mentioned earlier, the old pros from the 70's and 80's knew how to Mix albums far better. They were mixing an album assuming you had 500 watts of 3-way speakers at home. Today, they assume you are using cheap junk that they can hide a mediocre mix behind. Back then, over half the audience was being critical of the sound, now it just isn't much of an issue unfortunately.
Digital clips and not always at the zero point either. If you make a pure sine wave at any low to center frequency and keep it at about -12db, it is still going to clip to hell even though it is no where near the threshold. This is rarely considered in my experience. It happens to me occassionally. None of the recordings were clipped at all then when you render two sounds together you get clipping, even if the meter never hits the red. It's delicate work
Ultimately the goal is that NOTHING in an album should be distracting. Everything should be virtually transparent like the sounds are being played in their own aural space where they are supposed to be. You should choose to listen to an element of the music and all of them should be audible (except what is supposed to be hidden, ie, a keyboard playing underneath the bass guitar to fatten the tone)
They achieved this better back then. But the tradeoff is that now we have a much more individual way of working to get a sound. Individuality at the expense of accuracy. The only problem with that is that the long term or even shorter term consequences may make an album hard to digest once the little mistakes get noticed.
I think the actual people working right now are as good as ever, but some of them try to have a unique sound which is dependent upon deliberately ignoring conventions to the detriment of the albums quality. (example, Mutt Lange's overcompressed, overhyped kick drum sounds and thin snare sounds)