Pallas and RTI are both good, and Optimal is solid too. Part of this may be attributable to what the sound recording owner/label/client is willing to pay for and part of it may be equipment/personnel at the plants, but a huge factor in my estimation is quality control. I've had bad copies from virtually every plant; some are known to be horrible-- I just got in a great new jazz record and sadly, pressed at Rainbo, non-fill, stitching, visible defects in the surfaces out of the sleeve. This should have never passed QC at a decent operation but these companies are overwhelmed. The artists doing it on a small budget don't know in many cases or just go with the cheaper, quicker option, believing that 180 grams is an assurance of quality.
Every copy is sui generis in my view, but certain plants are better than others for quality and consistency.
The fact that Chad is vertically integrated doesn't have any meaning for me if it is not music I want to hear- I already have most of the warhorses, so I'm looking for more offbeat stuff, both in new and used vinyl. If you talk to somebody who uses these plants they can get good work out of GZ Media and Record Industry.
There were budget plants back in the old days. The Monarch pressings, which are highly regarded today as bombastic, were from a plant owned by Viewlex, which owned Buddah Records and Sonic, another plant that wasn't necessarily "high-end." In fact, the notion of high-end and record pressing plants is a misnomer---these were industries in their heyday, cranking out copies based on demand. The mass market wasn't quite as finicky as the audiophile market is, thus the "audiophile" record which started and in some ways still remains a niche product.