So I switched bike over to tubeless and installed CushCore inserts. Coming from XC bike with narrow 29x2.1" tires the 27.5x3.0" tires felt huge and I was having a little trouble feeling confident in turns with them. Just figured it was something I'd get used to. I had front tire at 26psi and in turns felt like tire wanted to fold over sorta... I dunno how to describe exactly. With tubeless CushCore setup running 20psi in front and totally confidence inspiring. I'm going to try dropping pressure further and see how it goes. It is pretty crazy to me how well CushCore works though. I'm totally impressed, I was not expecting this much benefit.
My XC bike has TannusArmour. I was getting tons of flats and after installing TannusArmour they went way, I'm not sure I've ever had a flat with TannusArmour installed. But that's basically all it did.. it added a little weight but I quickly got used to it. I wasn't really able to run lower tire pressure with hit. Tire seemed to behave the same as without insert. But I mean I'm happy to have no flats, but it didn't really improve performance at all.
Oh... one other note though, TannusArmour is easy to install.. maybe a little teadious but not at all hard. CushCore is really hard to install. Initially it was impossible to install. After watching a couple videos when I used better technique it went from being impossible to just really hard, lol. First tire took me over an hour, second tire I'd gotten technique down a bit more but still a half hour. But 100% worth it.