Now I get it...

You’re right, and I still play (and enjoy) the “terrible” ones.  Just never understood how much better a truly good recording can sound.  The SQ gap between good and poor seems much larger now (to my ears).    

Congratulations.
You now have the  gear. Avoid the darkside....REISSUES!

Discogs is your bible for original presses. 

I have found that beyond the situation in which you now find yourself, there is a promised land where your system can find the "good" parts of a badly recorded LP. (Can't do much about bad musicianship.)  Nowadays there are very few LPs that spur me to call a halt, get out of my chair and change to some other LP, just based on sonic nasties.  But before now, I did go through that period where my system made the bad over-rule the good, but the good sounded great. I can't put my finger on what makes the difference, but it is not that I added a bit of euphonia to the mix.  The right combination of cartridge and tonearm makes a big difference, but it is very difficult to predict what exactly goes with what, except by trial and error, unfortunately.

Funny sometimes it's your speakers connection came lose.People set up there stuff and forget about it....I may not be the pressing ,or your speakers, just a connection. It happens.

Welcome to the ever widening rabbit hole of audio bliss!

It gets dark in there.......