Well it's hard to tell because I don't have any hard data like a dyno chart to quantify the differences? My real goal was to get rid of the CAT's but not get much louder. To that end, it was well worth it to me. I compared the De-CAT's with the TOR's without changing any other variables and I could not detect any significant power difference, just that the TOR's were slightly louder at any RPM's above 1500. A little deeper tone too, as you might expect. The TOR's cans are thinner and the single barrel baffle is 2" diameter compared to the stock baffles that are 1.5" diameter with a thicker shell to accommodate the heat of the CAT.
Logic would tell you that while I can't feel any difference performance wise, the TOR"S would breathe better at higher outputs? So if you were after maximum performance and didn't care about increasing the noise or doing a lot of other expensive mods to achieve that then I think it would make more sense to go with the bigger bore to match it.
One other advantage to taking the CAT out is it doesn't get nearly as hot?
Your avatar says you have a touring and I don't know what the inside of that pipe looks like? Could be different. If I see one cheap or damaged I may get it just to find out? Curiosity kills the CAT! I couldn't help it