LP's... Do they sound better now than 30 yrs ago?

There’s a ton more RFI/EMI now than there was 30 years ago. So, all things being equal, LPs definitely sound a lot worse now. Final answer.

Modern LPs including 180 gram heavy pressings sound a lot worse than vintage. Of course, there are a few exceptions and the quality of source material is essential, as ghosthouse pointed out. I have learnt my lesson and have stopped buying reissues and seek for original pressings only, unless they are hyper expensive rarities I really can´t afford.
Just recently, after a very long time I revisited "What Were Once Vices Are Now Habits", 1974 orig US edition by The Doobie Brother and the sound is quite unbelieveable, I never new it was that good - what a clean and yet so dynamic recording ! A very nice surprise, after about fifteen years :)

I´ve never cared for "backround noise" as it depends on certains variables on production, the actual signal (above backround noise) is all that matters really. I don´t care for little surface noise (pops) and I`ve never cared for tape noise either, actually I record LPs to c cassettes without noise reduction (Dolby) and listen to them in my car, and in home.

they sound like typical reissues or worse. often lacking original dynamic headroom (yea compression) and also priced unreasonably large. used originals are cheaper an sounding substantially better. 
classic records reissue of black sabbath is one of the typical examples of how pathetic these are.

@harold-not-the-barrel - Funny you should mention that Doobie Brothers record - "What Were Once Vices are Now Habits". I just listened to my original 1974 US release - W 2750 last Saturday night with one of my music loving friends and it sounds amazing! My buddy was shocked at how awesome it sounded on my modest/moderate system. Really good music and excellent sound.

reubent, you have got a great taste. Yes, I know it has always sounded awesome (all those decades) but today w/ HQ system it sounds terrific :)