I figured I'd make a whole new thread for everyone to put their reviews in, so people are sifting through 5 pages of the original planning thread to get to them, or having to find a bunch of individually posted ones scattered all about.
First, the clips:
Vintage Strat block
Installed in an MIJ Fender Strat, stock pickups.
Floyd Rose block
Installed in an LTD Alexi-600, Seymour Duncan PATB1 pickup.
(all clips are stock block first, Killer block second)
I could do them individually, but my review for both are pretty similar. As far as appearance, construction, aesthetics, etc. both look very nice, have a nice solid feel to them, and are well-made as far as I can tell by my short time with them. Putting the Killer block in one hand and the stock block (from either of my guitars) in the other, the difference was ridiculous. It felt like the stock blocks weren't even there. As far as installation goes, the only differences were inherent to the type of bridge being used. The vintage strat block was a quick and easy change. The floyd block was an overwhelming pain in the ass, but thats just because its a floyd. Nothing to do with the block itself. One tangible difference is that the Killer floyd blocks have spring retainer bars, an additional bar of brass that gets screwed over top the ends of your springs. I think thats a terrific idea. More mass, more contact. Can't hurt. Last thing to mention installation-wise is that both Killer blocks have dramatically deeper screws going through the bridge into the block. I'd say roughy double the stock block/screws. This is also a nice feature; more secure, more contact.
Once the blocks were on and the guitars were ready to play, I could definitely feel the difference. Unplugged, I definitely felt more vibration moving through the guitar, and you could hear the acoustic sound more loudly as well. Thats not to say it was fixed bridge resonance. It still felt and sounded like a trem-equipped guitar, just amped up. Plugged in, I anticipated that these new blocks would make the guitars sound thicker, fatter, heavier. You can definitely hear the difference, check the clips for example, but I don't feel that they became thicker. Instead, the new blocks made each guitar sound punchier, cleaner, more articulate and with more bell-like qualities. In stylistic terms, I lost some chugga-chugga and gained more pretty. The strat really benefits from this, as the stereotypical chimeyness of a strat is brought out even more. That bell-like ringing and clean articulation made my strat strattier.
After the block lotto is over, and if I come up empty handed, I'd definitely think about buying a block for my strat. I can really describe it no better than "making a strat strattier." For the floyd block, I feel like the benefits of the new block were definitely present and I think it sounded really good in person, but at least in recording I feel it sounded less-suited towards chugga chugga metal. Though those recordings are guitar-only...in a mix, the Killer block would most likely stand out more. I wish I had thought of that earlier...damn. I'd also love to compare it through a real amp, but unfortunately due to time constraints I only got to play through a modeling practice amp and the recordings were all POD.
All in all I was very pleased with both blocks, and HUGE thank you to Killer Guitar Components for giving all of us this opportunity.