I've got lots of MFSL pressings, some CBS 1/2 speed masters and other alleged high quality pressings. I've also purchased one new UHQR pressing at MSRP to see what all the hype was about and sold it for about $150 more than I paid for it. I also had a subscription to Music Matters 45RPM Blue Note Jazz records for a couple of years when they first started up back in the day.
AS a general I find that anything MFSL puts out is a quality LP. Not always, but by surely, the vast majority of the time. They tend to be a bit heavy and sometimes too heavy on the bass. They are always quiet. The 2nd generalization I would note is that if you are buying them (any audiophile pressing) used they typically have been well cared for. So there is a lot less risk in an ebay seller saying a LP is NM- or VG++ and you getting it and it sounding like it was played with a rusty nail. It makes sense that anyone buying a MFSL or other quality pressing in the 80s took care of their S#it, so low probability of getting a lemon. All the Music Matters 45s and Classic Records 200g pressing are fantastic that I have personally heard. You pretty much have to buy them when released before they go OOP as the 2nd had market is crazy expensive. Try buying the Classic Records Led Zeppelin 200g LPs today...you need a 2nd mortgage. Pretty safe bet that if you buy them and don't open them you can at a minimum get your money back. But what is the point in that? They are for listening not collecting in my book. I'd suggest buying a few of something you know well and making your decision. If I want or need the LP and it is available at retail I'll buy a MFSL/Music Matters/Classic Record every time over a standard LP or more standard 180g pressing, especially if they don't say mastered from original tapes on the standard LP.
The UHQRs are worth the price of admission if you can pick one up when they come out. The packaging alone is a sight to behold. The Aqualung LP I had sounded great, but in the end I rarely listened to it because I felt like every time I did it was lowering it's value. And I was not a huge fan of the LP originally so it didn't get much play anyway. Better to sell it to fund things I actually play. Beyond 50-100 bucks I'd say they are not worth it.
That said some of the recent prices are simply fantasy. Check the sold transaction prices vs. the asking prices on eBay. Most make offer listing that actually sell show the seller agreed to a different price. Ones listed at auction that sell truly reflect the market value. Typically too rich for my blood.