I finally decided to buy the DVD download - about half the price of buying the DVD + postage.
Overall I'm happy with it, here and there there are problems (page edges cut off, low quality images, crinkled paper, image processing errors/skewed pages) but it's better than nothing, and even on the worst pages, still mostly readable, though some schematics are basically unreadable due to a low scanning resolution. Sure, nobody's likely to ever build them these days, but it's still annoying - and if you DID want to build them or use them for restoration etc - good luck with that!
Would I get better quality if I scanned them all myself? For sure. But would I be able to find every issue for a lower price, and scan them faster than buying SC's copy? I doubt it.
It's fascinating to read these in any case, from the perspective of an era I was never in, and for the entertainment and general interest alone I think it's worth it. It's also quite refreshing to read articles from a time when articles were written for people who actually bothered to sit down and take the time to read them, rather than so many now who just skim mindless tweets and farcebook.
Hopefully this will make anyone else's decision to purchase (or not!) easier.