I have been shooting the BossTom 2oz 20g loads for the past 4 or 5 years or so. Back then they were $45 a box, cheaper than any 1 5/8 oz loads I could find.
I've been very pleased with them in my 870 youth compact with .562-5 Sumtoy. even 240/240 pattern or so, but def a few more flyers outside the 20 (prob from the constriction). Everything has died it has been shot at.
I'm down to my last 3 of those shells, and won't use them again. Not that I haven't been happy with them, but because they have now gone up to $60 a box. I've got a ton of other brand TSS I've bought on sale in the past few years for $25-$35 a box and will be using them instead when I fire my last boss tom.
I will say this, they initially claimed 1150 fps when I bought them. I ran them thru my chrono and was only getting 1050 fps, which makes more sense. They have since updated their website to reflect accurate velocity. And now looks like they offer a 2 1/16 oz load, I guess just for those who only look at payload and think it's everything.
I guess bottom line is... i don't give a rip about the shell when it comes to TSS #9's. They are ALL gonna be a 100% dead bird at 40y and in unless I pull the shot (which I don't, thankfully). They are all so far overkill I opt for the cheapest one I can find. I suppose if you were wanting to shoot birds at 60 yards, tweaking for an insane hot core would be worth it.... but the day I intentionally shoot at a bird at 60 yards is the day I quit hunting them.