Besides Aja and zeppelin pressings, what others are demo level recordings?

mijostyn

It is not the pressing that is important although quiet is always better but the quality or the recording and mastering

Nope. Wrong. Its the pressing. One White Hot Stamper and you will know.
Mingus? Miles? Name your poison.
https://www.better-records.com/search_adv.aspx?sp=mingus&option=s_name&min_price=1&max_p...

Look into Tracy Chapman and Chris Isaak.

MusicMatters Blue Note stereos, Analogue Production jazz pressings, Dire Straits albums, originating Blue Notes in good conditions, Bill Evans.

Cecile Mclorin Salvant: Dreams and Daggers. Absolutely gorgeous sound. The 3 LP set is a combo of live and studio recordings. 

Any Analog Productions album. Janis Ian's Breaking Silence is a nice start. It is hard to believe how good the Buddy Holly recordings are. These are handily the best quality vinyl made in the States. Substantially better than regular Mobile Fidelity discs and easily the match for their UltraDisc pressings. wakethetown is very right with Dreams and Daggers.
Cecile Mclorin Salvant may be the modern Ella. Her control is that good. I have the high def version so I can speak for the vinyl but buy it anyway. There is no modern jazz vocalist that is this good and I am including Cassandra Wilson in that comparison.