1. There was a thread on this question last December called 'Re-issue vinyl vs. the original pressings' which is well worth checking. My comment on that thread was
2. I would add that the above applies as a general rule only to originals pressed in the country where the recording was made and before about 1970 in the US and about 1973 in the UK and Europe. Otherwise, I think you have to compare originals and reissues on an individual basis, although some generalizations also can be made about specific labels, both original and reissue.
I fully agree with the consensus that most original vinyl pressings are better than the reissues and also that there are some exceptions. I have had not had a chance to check myself, but I did hear recently from a source who should know that the Classic reissues from the Everest catalog are as good as or better than the originals.
2. I would add that the above applies as a general rule only to originals pressed in the country where the recording was made and before about 1970 in the US and about 1973 in the UK and Europe. Otherwise, I think you have to compare originals and reissues on an individual basis, although some generalizations also can be made about specific labels, both original and reissue.