I always think that it's funny when people say that something "wasn't mastered for vinyl" or "was only mastered for CD" - not that you actually meant it that way of course - because mastering for vinyl is a process where the audio path has to be much more stringently controlled and restricted than for CD mastering.

Vinyl doesn't allow the presence of much out of phase content, for several reasons. OOP content occupies lateral space within the groove, and too much of that can make a stylus, or even a cutter head while mastering, jump out of the groove. Therefore, all OOP content, which can often be desirable from a creative point of view in mixing - as in making sounds fly around the room and sound and even feel awesome - has to either not be included in the mix at all, or the low end of the whole mix has to be "bass phased" - basically made into mono artificially.

On top of that, really low frequencies, partly for the same reason, cannot exist on vinyl, so low end has to be filtered out.

Similarly, high frequencies and sibilance can distort vinyl easily, so they also have to be tamed as well. Of course, a good mix probably shouldn't have too many nasty things in it in the first place, but I've seen phenomenal sounding mixes cause problems in vinyl mastering, simply due to the restrictions of what can actually be cut onto the lacquer. It's often a crapshoot.

I witnessed a situation that went on for days where Ray Staff, the chief mastering engineer at Trident, was having trouble cutting a Cat Stevens album. It sounded really excellent, but simply couldn't translate to lacquer without either skipping or distorting horribly. That meant having to go back and alter the mix substantially - which actually wasn't a wide or sibilant mix at all - so that it could even be cut. To this day, that particular case still remains a mystery, but there was just a weird combination of things that literally prevented several of the original mixes from making it to vinyl.

So, taking an album that was mixed without any consideration that it might even end up on vinyl at all - and trying to master it often results in using a lot of restrictive things like low end filtering, bass phasing and the like. Therefore the whole low end curve and spatiality of the vinyl version might well sound totally different to the CD version.

None of these unfortunate restrictions are actually present in the digital world. I spent the first decade of my career both discovering, and then trying to work around limitation after limitation of getting a nice, wide mix onto vinyl without causing problems for the cutter head, or frying it with too many high frequencies. Once digital came out, I was finally able to take home a full-frequency, unfiltered version of the mix, rather than one that had to be compromised for vinyl.

Combine that with the ever-present clicks and pops and bangs, and vinyl can go and jump in the lake for all I care.