Well if you already have the stereo and mono on vinyl it's not really nesicary. If you don't it's a good way to start. I have heard some better pressings but it's not bad at all. The stereo is vocally closer to the mono then what came out in the nineties on vinyl and CD. One good thing about this set is that it has more notes and info then any other vinyl release. So I do kind of recommend it, but it's not essential. Remember to get the real mono Pet Sounds you have to get a pre 1990 pressing of either the various vinyl LP's or Japanese CD. There is a cough that was cut out of Here Today but it removed some of the echo too.
Thanks, I know enough! Esp. the qualification about the stereo vinyl in that set... might be precisely what I am looking after!