I rarely rate anything 100%, since it implies perfection and leaves nothing for subsequent efforts to improve upon. In this case, it's completely warranted. I was given this collection as a gift, so the seemingly excessive price isn't really a factor in my review, but I'm pretty sure it's worth it.
The packaging is insanely lavish and detailed. My childhood home was littered with 78 rpm records that my mother brought from her job at a music shop. When I first took this collection out of its slipcase, I was instantly transported back to that time: all that's missing is the wonderful smell of well-aged paper!
As others have mentioned here, the fidelity is spot on. That's not to say they're noise free, far from it. In fact, the Patton material on the Yazoo collections is technically cleaner sounding in some cases, but by comparison lacks the detail and immediacy you get here. I've always maintained that part of the fun of listening to restorations from this era is the mental time trip you take, and the scratchy sound helps IMO. If it had been cleaned up any more, it wouldn't sound authentic, and might very well be missing musical information as well. Here, you get the real deal, and it doesn't take long before you don't even notice the noise.
But all this would be for nothing if the music wasn't so great and deserving this treatment. Besides the Patton material, there's stuff from Son House that makes my jaw drop, 8 gospel tracks by the Delta Big Four that make me want to find religion, and lots more.
Finally, to anyone who had anything to do with this release's production: if you don't win a Grammy, TANFJ (there ain't no justice). You deserve it!