How much better are MFSL disks?

Than just run-of-the-mill pressings?
They have a much better resale value. That and they sound better too. I always regard them as high quality recordings for the reason any listener would. Run of the mill is a category I suppose that are made for DJs, the majority of other lables are high quality Audiophool pressings.
Like most things in life, MFSL LPs are better, merely different, and sometimes worse on a case-by-case basis. It also depends on whether you are comparing an MFSL to an original pressing or a reissue. Yes, they have excellent resale value, but sometimes they don't warrant it intrinsically. Good listening!
That is broad question so I will answer it this way. As a general matter I have found MFSL disks (assume you mean LPs not CDs) much better sounding than the average retail pressings. That said many titles that were issued by MFSL have since been reissued as 180, and 200 gm reissues or can be found either as Japanese or European imports. There are many previous threads that discuss the quality of various reissues including comparing them to the MFSL pressings.
I own a number of MFSLs, some gold. As my system improves they sound better and better
The sound quality varies from disc to disc.My Hotel california is amazing where as My Crime of the Century is not as good as a Canadian Audiophile pressing I have. You now can compare MFSL with various versions from Natalius and other specialty pressings like DCC and others.
its all about the masters
I stopped getting them. They sound excellent on a cheap/average analog System but they don't move on with a better system.
The original pressings are different (in general), they get better and better with top analog playback chains.
And most MFSL are not true in tone compared to the original.
Resale is good.
Yes, the resale on any MFSL disk is extremely lucrative. I have a couple sealed MFSL LP's that I wouldn't dare open and play due to their value. Once in a blue moon I'll play my $165 copy of "Aqualung" that, IMHO, sounds superb to any release of this album. The remastered CD sounds horrid.
Thanks for the responses everybody. I'm very new to Vinyl. Is there a good web-site resource for links and information on quality pressings?

Some MFSL vinyl releases are better than their 8-track and cassette counterparts.

But not many.