I just wanted to emphasise what others have said here about the remixing of the tracks on this album; if you decide to buy it, be aware that it really does sound very different to the original versions.
I'm no purist on these matters - I think far too much fuss is often made over remastered releases of albums where essentially all that's different is the tonal balance - and you can compensate by fiddling with your bass or treble controls until it sounds the way you think it should.
However, in the case of this album, the songs have been remixed from scratch, thereby allowing the sound to be drastically altered. What's worse, this seems to have been done with a very 1980s ear, completely at odds with the aesthetic and spirit of the originals.
In practice, what this means is lots of extra reverb, particularly on the drums and vocals, and, unless I'm much mistaken, a much louder snare drum.
I find all this pretty incomprehensible - Bob Clearmountain, who was responsible for these mixes, is a hugely well-respected and talented individual with a world-class reputation. What WAS he thinking?
Maybe this doesn't matter to you. The songs and playing are, of course, top notch, and the sound quality, in itself, is fine. It's just... this isn't what these songs are supposed to sound like.
There are other Free compilations here on Amazon, though mostly 2-disc compilations as opposed to this single disc version. At present, there's the venerable "Free Story", "Walking in my Shadow" and "Chronicles", and possibly more... I would seriously recommend that you investigate them instead of this.
OK, enough of this; I'm off to add a horn section to "Nevermind", and autotune everything on "Pet Sounds"...