I have used Dexter SST5s, SST6s, then 3G Tour Ultra, the SST8 and starting next week, back to the tour ultra.

I get years out of each; but as someone that drags my toe I tend to wear out the right shoe pretty quick.  The reason I am ditching the SST8s is that dexter took them ambidextrous; both shoes have the Velcro for replaceable soles and you place a rubber sole/heal combo on the non-slide foot.  They did this so that the same pair of shoes works regardless of slide foot.

for me, my toe dragging has killed the Velcro on my non-slide foot and the rubber sole falls off on my approach or in the slide.  I have been sending the rubber sole 2 lanes over on my slide.  I am returning to 3G tour ultra's because the interchangeable aspect is on the slide foot only.

in terms of comfort, no complaints about the SST8s but the tour ultras they replaced were better, and I expect that to be the same once the new pair is broken in.

Totally off topic, it is amazing to me how some guys have top shelf bowling shoes yet have the nerve to wear $19.99 "Air Dad" specials from Kohls.

I don't drag my toe, I don't need ambidextrous. Do the Dexters use a different form of attachment for its pads than the TPU's and Tour Ultras?

I have had my 3G Tour Ultra's for over 4+ years now. I did have an issue with my toe cap splitting from drag. After I repaired the split with super glue, I took a piece of velcro and glued it on the end of the cap. This has helped from it from getting worse and it does work. I recommend the 3G'S.

There are so many variables that it's hard to make absolute recommendations. Just about every high end shoe is going to have its fans and detractors. Feel means far more than features on paper.
 
At the two ends, from most comfortable to most supportive, the best of breed are probably the TPUs and the 9s. I've owned or tested most high shoes available and these are the two that stand out.
 
It's hard, but you have to try on the different shoes to know what feels best for you. That's one of the cool things about Nationals. The different booths carry most of the high end shoes available.

Anybody know anything about the Pyramid shoe's that have changeable soles and heels? I want a good shoe but I'm a bowler on a budget

 
I have the Pyramid HPX, which are the same as the Brunswick TPUs. For $100, they're very good shoes. I had a shoe repair shop cement a piece of leather to the tip of the non-slide shoe to eliminate any dragging wear issues, and they're wearing great. I have between 200-300 games on them, and they still look almost new.

Since I'm using the Dexter Pro Am II, what interchangeable pad would this be equivalent to?

If I get a pair for next season that allows changing them, I want to get at least 1 that's equivalent for the adjustment period and because it works a lot of the time.

Either the 8 or 6 slide (numbers are fairly similar across all companies). I want to say the latter but it's hard to say. Haven't looked into these shoes for a long time.

For what it's worth Buddies still has the Storm SP 800 shoes, made by Dexter, on sale for $85. Lots of sizes available too. For a shoe with an interchangeable sole and heel that's a really good deal. Comes with the S6 and S8 slide along with two different heels.