Quality system, make poor recordings sound better?

It partly depends on why a given recording sounded bad. Was it overwhelming the limitations of your system, or truly a poor recording? 

A better, more revealing system will allow better recorded records to sound even better, while showing off more of the flaws in a recording. You're going to get good and bad. A lesser system tends to mask flaws. 

Better systems not only will reveal more harmonic detail, but well give you a more layered and detailed soundstage, and a greater variety of dynamics, from very small to very large. You'll hear a greater difference between recordings.

My experience is the same as many of you...

If the system/room improve all albums are more interesting Why?

Bad recorded album stay bad recording and well recorded stay good compared to the first....

Yes, but all acoustical cues choices by the the recording engineer become more evident and audible and we are more interested now by the relation between the music and the acoustical cues fabric cloth that reveal it, like a more adjusted piece of cloth on a body....

it is better than more details emerging, it is a new soundscape...

But nothing will change a bad recording in a good one for sure...

The difference is you will no longer listen good recording because the bad one are so bad... All will be interesting and in the best case you will forgot the recording ,bad or good, and enjoy music without be frustrated anymore...

It is my experience...

When i begin my journey few years ago i was picking my listening way more in the well recording category than for the music itself... My system/room was not treated and not controlled at this time... No more now....

An easy way to improve any CD is to clean and improve reflectivity. I use a high-grade Groit best-of-show car wax, one drop is all you need, spread and buff, and you’re done. There is such an improvement you will not believe it. All you have heard is just shake their heads, dynamics, body, and tone all come forth. I’ve not played an uncleaned CD in many many years, I do try sometimes so I will clean a CD with soap and water to wash off the wax, play it and it sounds good, but nothing like it sounds before. No need to buy audiophile-overpriced liquids. $20.00 or so and you have enough for 100’s of CDs. I’ve taken some of mine to audio shows and played them and people say wow that sounds good, who mastered that I own it and I never heard it sound that good. CDs were turned on over the past several years, from being used as sources in the SOTA system to they sound like crap now. I guess all the reviewers had crap for ears back then. I am a vinyl guy and I have zero issues with CDs if mastered well like any source and cleaned with my wax.