There's a reason chess.com gave his show the boot.
It was the worst show on here. His Q&A's offer no substance whatsoever, and his advice is completely wrong.
Im 99% sure he's friends with the authors books that he reccommends. Chess Tactics for Students is the most basic book out there. And he reccommended it to a 1600 USCF player.
Just... no.
I actually spent about 2 months trying Heisman's rec on 'easier' tactics where you can get 80% of them right, and fairly quickly. I acquired "Chess Tactics for Intermediate Players" by Convekta, and those seemed exactly the right level for what he was recommending. My score in those was pretty near what he recommended - 70-85% correct, and I repeated my erroneous problems.
It actually totally failed for me, dead honest. And I'm predominantly a blitz player, so I would have expected it to help! What ended up happening is that I started to calculate too superficially - if I couldn't find 'the win' in 20 seconds, my brain would give up. As expected, that's really bad, even in a 5-min blitz game!
Contrary to what he and other says, if I do study tactics and want them to help my play, complicated, longer calculational tactics do seem to help. Even if I don't find tactics that complicated in my games (ones of that caliber rarely crop up, as per Stockfish), it's seems to pull my 'easier' tactics vision up a lot, as well as my computational abilities.
I suspect that kind of tactical study would help my bullet play more than anything else, but for sure, I suffered a nearly 100 point sustained rating decrease after doing the Heisman tactics approach. Since then, I haven't ever opened that Intermediate Player Tactics program in fear it'll make me a worse player again!
As I've said on other posts though, studying tactics for me has been markedly inferior than studying full annotated games. Studying more tactics barely makes a dent in my rating, whereas studying (and trying to memorize) annotated games seems to ALWAYS help my play, regardless of speed (bullet/blitz/long.)