buying what you already own

Bob Mould. That one guy has been responsible for so very much of my musical taste that there's no way I can "review" the newly remastered and re-released Copper Blue/Beaster.  I know these songs backwards and forwards, can play all the guitar notes, know the lyrics so well, I sometimes hum them in my sleep, and therefore, have played some of these songs as covers. The only question I can answer for you is why you need this, as opposed to just owning the original rykodisc pressings from the 1990's.
The first reason, though not the best reason, is for history. Bob invented the kind of pop music enveloped in squall that everyone from The Jesus and Mary Chain to the Constants has used. Sugar was his response to the best imitators of his sound: My Bloody Valentine and the Pixies, so the most obvious reason to get this is to hear his full response to his place in musical history.
The next, better, reason is that these two CD's represent Bob's most accessible work, ever and the new mixes make sound clearer, deeper, and better. If there's one release to suggest, this is it. If you tell me  you don't care for Alternative Rock, this is still the one to get, as this set has everything from gothic folk pop to out and out shredding.
Since chances are, if you're reading this, that none of the above applies to you. You already own at least Copper Blue, if not Beaster, and Besides, and maybe even a bootleg live LP or two. Why get this this?
Because it collects everything that belongs together, and it's on merge, which means it's a "fan" version of events. I can understand this- when the albums were brand new recordings, they had to be "sold" to us- we needed convincing, so the editors' hands had to guide this towards what they thought we wanted. Now, there's no need to sell this, as Bob has legions of fans, so instead, they can release everything grouped together in a way that makes sense for the existing relationship. Not to read too much in, but if you were there the first time, like me, this is how you have wanted to hear Sugar.