Neither. Get ready for this...
This is taken from a Steve Hoffman thread that I have been following for more than a year. The OP's username is rjstauber. I have bought/tracked down all versions talked about, and I agree with all points.
1. Black Sabbath
This is probably the most complex album on CD. We have two different track listings, the original UK vinyl with Evil Woman and the US vinyl with Wicked World. Well, I like both these songs and want to have both of them in the best possible format. In order to compile my favorite version for all tracks, I need two or three different CD versions:
For the best sounding side 1 of the original album and for the best sounding version of the song Evil Woman, I recommend the first Japanese pressing (33PD twofer which doesn’t have the long song Sleeping Village/Warning and which also features the album Paranoid) or the 1986 Castle version (CLACD or NELCD prefix). These two sound quite similar, and I haven’t finally made up my mind which version I like better (right now I slightly prefer the 1st Japanese pressing, which is a tad brighter but a little more defined).
For the best sounding side 2 of the original album and for the best sounding version of the song Wicked World, I recommend the Creative Sounds CD, but: You must make a CD-R copy of this CD and manually set the PE flag in EAC, since the PE flag is missing on the original CD. The resulting CD-R sounds awesome in my opinion.
Now you are probably wondering, why the Creative Sounds CD doesn’t also make the perfect side 1 of the original vinyl? Well, there seems to be some kind of tape alignment problem from approx. halfway through the first song to somewhere in N.I.B. Sounds like an azimuth error or something. Otherwise, side one would sound awesome as well. Just compare the first half of the title track, it is mind-boggling.
If you don’t want to mess around with all of this, the early Castle version is a good choice, but it doesn’t have Wicked World.
My favorite version is the first Japanese pressing (33PD twofer – see above). The 1986 Castle is a good second choice, but sounds a little muffled in comparison. Some people also prefer the 2nd Japanese pressing (23PD), but it has too much EQ for my taste.
3. Master Of Reality
My favorite version is the 1986 Castle version (either CLACD or NELCD prefix). It’s a little on the dark side, and some people might consider it muddy, but it sounds great and very natural to me, and you can really crank it. I like it better than the 1st Japanese pressing (another 33PD twofer, together with Vol. 4).
4. Vol. 4
Same as with MoR, I prefer the 1986 Castle version. In this case, it is by far my preferred version and I haven’t heard a version which comes close to it (that includes the 33PD twofer).
5. Sabbath Bloody Sabbath
My favorite version is also the 1986 Castle CD. I prefer it over the 1st Japanese pressing (23PD).
Similar as with the first album, my favourite version is made up of two different CD’s. I have to say though that I never heard an early Japanese pressing of this album. The US Warner Bros. CD sounds pretty good for this album. It seems to be made from the right tapes, but it sounds a little harsh at louder volumes, especially some of the heavy rock tunes like Hole In The Sky. The early Castle CD from 1986 sounds a little more natural, but it has some tape problems during Symptom Of The Universe and Megalomania. To me, side 2 of the original vinyl sounds better on the Castle, but you need to have the US Warner Bros. for those songs with the tape problems.
If you don’t want to deal with different CD versions, then I recommend to just get the US Warner Bros. CD.
7. Technical Ecstasy
I have the 1st Japanese pressing (23PD), and it is the best I have heard so far. I once compared a clip of the US Warner Bros. CD to this, and it turned out to be digitally identical. There could still be minor differences due to different pressing quality, but I am not going there in this thread (I am only talking about clearly different masterings here).
8. Never Say Die!
I have the US Warner Bros. CD and think it’s o.k. As far as I know, there is no early Japanese version of this album (not in the 23PD series). It’s not my favorite album anyway, so for me the US Warner Bros. is sufficient.
Also, if you are not adverse to going on the "little green man" website, a user with the name of pbthal has needledropped the best vinyl versions of the first six albums. They sound friggin' amazing!!!