As for the simulator, I don't blame you for waiting. If we look at history how many products have companies released to only redo them a year later cause of problems. Lets see how these work 6 months from now, if they work this will be great. Also another more affordable option may come available.
Don't forget going to a catless DP will increase the exhaust sound by alot more than one with a cat. But a good high flow operating cat shouldn't affect HP.
When we made our downpipe we did put a cat in it. This raised the cost but also found it worked to keep off CELs. But I do admit some cars still get a CEL, usually the newer ones. They seem to be more sensitive. The Catless option would be alot cheaper to make and sell.
Either way I'd make sure you get it ceramic coated to heat control.
