The Hybrid is actually pretty good, much more efficient than the Core, smooth, and easy to use. I'm getting 4 good shaves per blade, but haven't used a KAI or GEM blade yet. The Hybrid is a keeper, and I had returned the Core.
Basically 95% of the Genesis, at a whole lot less money.
KAI Best (FAS-10), they're carbon steel....not quite as smooth, particularly the 1st shave. They are drop in compatible, although they seem a bit tight, at least the .245 blades.
I have the mostly the same experience as you, but I do get the same blade life regardless of Hybrid or Core. I get two good shaves and can get two lesser shaves.Unlike the Core, which gave 1 decently good shave, then 1 meh shave, the Hybrid is good for 3 quite good shaves, and 1 that takes a bit more work on a single FHS-10 blade for me. - I have stiff gray growth, so there's absolutely a huge improvement over the Core I tried in 2017. It's actually possible to get a weeper or tiny nick with a Hybrid, if you're sloppy enough, and press way too much.