Choosing between Reissue and Original pressings

At the end of Day: Each his own:- )Unfortunately a lot of Press Plants
closed in the 90's and most Know How is gone. Now only a few do it,
more or less good, but honestly, only a quality shadow from those
records we got in the 80's++. From my experience, most reissues are
horrible from quality, hardly a side which is completely silent. Acoustic
Sounds always made a good job, maybe a few others, too, but in general
these problems have nothing to do with the Playback System. I think,
sooner or later we will find cartridge designers who offer round needles
again, because they are not so sensitive (Lyra Kleos for example is made
for those). But this is like riding a dead horse...MP3 sound with vinyl

Reissues can't be better than an Original, this is technically not possible,
best what can be done is to get it as close as possible to the Original
one, but normally they are worse (you can hear it immediately in the
higher frequencies and in the tonal colors). Listening with a cheap
cartridge and Originals is better than with expensive carts + reissues. It
is a matter of experience....

Sometimes the reissues turn out better then an original release. However today I no longer buy re-issued anything, If I have to own it I hunt down an original release , it may have noisy surfaces but at lease the music is a live.
I think the only company you mention that accually did a good job at re-issues was Classic. A couple of examples of poor re-issues was particularly from Speakers Corner and Mobile Fidelity. Speakers Corner with their Mercury Living Presence and decades before Mobile Fidelity with their entire catalogue, a myth has carried on over the decades about their re-issues very few are accually good.
Don't rely on positive chat over the net or favorable reviews ,find the 1 or 2 % that don't like it and put your faith in what they have to say.

If I had to choose, in the abstract, between an original pressing and a
reissue, I'd choose the original (assuming, as you are asking us to, that it is
not impossibly priced). Boxstar is a good example. I like Janis Ian's
Between the Lines and have a number of copies, both originals and the
Boxstar 'audiophile approved' reissue. I fired that up a couple months ago
and thought something was wrong, it sounded flat and lifeless. I put one of
the old CBS pressings on, and whooosh! Back came the life. Ditto, on a
similar experience with a not so mainstream jazz recording of Amina
Claudia Meyers saluting Bessie Smith. The original, on Leo Records,
sounds very, very good- particularly the piano. I bought an audiophile
reissue to have as a backup. It sounds dead and at two removes by
comparison.
The difficulty with the originals (and in both cases mentioned above, the
originals came from an era that was not a high water mark in vinyl quality,
circa 70'-80's), is condition. Buying used, even 'mint' is not mint in my book-
noisy because of what it was played back on in the day, or worse.
I don't know why remastering engineers have to change the sonics in a way
that is sterile. Maybe it is the condition of the master tapes (assuming they
are going back to original tapes, which may be a big assumption).
In some instances, the reissue may be better only because the pressing
quality of the original was so bad. Here, I'm thinking of the Shelby Lynne
'Just a Little Lovin' record- the Lost Highway pressing is just unplayable. It
is defective. And the copies I had were not anomalies in this regard. You
have to buy the 'audiophile' version to get one that's playable. (And even
those have uneven quality control from what I gather).
I'm sure I could think of other examples where the reissue is acceptable as
an alternative~ but often that is because the original is impossibly
expensive.
How do you know which is better if you had a choice? You don't, without
playing it or relying on someone you trust. I don't necessarily trust
reviewers, having bought a few records based on positive comments about
sonics- either we don't share the same view on what sounds 'good' or our
taste in music is fundamentally different.
I've had decent luck finding some 'pop' records from the late 60's- early
70's that sound really good, but there may be copy to copy variability. Two
examples: the second Blood Sweat and Tears record can sound startling, if
a little bright; ditto a couple sides of Chicago II. (One of the sides on that
record sounds nasty, i can't remember which, and maybe it was my copy,
but even on the same copy, there may be differences in the sound from
side to side). Final observation re a well-known record: I have had
innumerable versions of Tea for the Tillerman, including the UHQR which I
bought new. The best is the pink label on Island, pressed in the UK. The
pink rim is also good. All the other reissues sound ''less good.' But the pink
label is a known commodity and is priced accordingly.
Sorry for the long post.
Postscript: the Classic reissues on 45 can be very good and in the case of
the RCA 'dogs' are quieter than the originals I have. But I had a lot of QC
issues with stitching and 'no fill' and quit buying their records at one point
when they were still newly and cheaply available because I didn't want to
put up with bad pressings. So, even where there could be an improvement,
it turned out to be illusory.

Thanks everyone for writing elaborate posts on this topic. This is a very important subject especially for people like me who has just started building their record collection. When I visit a record shop I see tons of options and it becomes difficult to choose. Apart from the Audiophile reissues there are other variations of the same album, like:

1. First pressing
2. Early pressing
3. Early reissue
4. Pressed in so and so country (mostly specified if it is a Japanese pressing)
5. Early reissue by a famous XYZ label (like MFSL)

First pressings are rare but early pressings are found more often. In such cases do you favour "country of pressing" ? If yes, then how do you rank them ?

Coming over to reissues, an album like Muddy Waters "Folk Singer" has been released by MFSL and Analogue productions and of course there must be the original pressing of it. What do you do in such situations ?

Fleetwood Mac "Rumours" reissue, remastered by Steve Hoffman is generally considered much superior to the original (I havent heard the original though). Question is, if a reputed mastering engineer is involved in a certain reissue (Steve Hoffman, Bernie Grundmann, Bob Ludwig etc), does it make a good case to buy the reissue ?

One more question, is it possible to detect the original pressings from a early reissue ?

First pressing? By that Pani I assume you mean the first stamper.

If so, the desirability of the first stamper escapes me, as with the RCA S-1s. It would seem the critical issue would be how many records a given stamper pressed. So would the fifth pressing from S-10 be worse than the 1500th from S-1?

But I don't know how many records S-1 stamped out, nor do I have any idea how to even guess which pressing a given record might be within its respective stamper's life.

So bottom line, it becomes a matter of auditioning any two pressings of the same record. And yes, I have heard significant differences.