Absolutely... just between the TRD panel filter, removing the post filter in the air box, and installing this exhaust the car feels a lot different. It was definitely being choked from the factory. Best part.... my fuel economy has actually gone up (just 0.5mpg, but that's still something). I'd recommend these modifications for anyone with a pulse.
Just search Amazon or eBay for "Magnaflow 12645" I think I paid like $97 with shipping, and the local muffler shop charged like $60 to cut out the muffler behind the cat, and weld this in with a couple hangers.
Just an FYI, if you guys are looking for parts from toyota, then buy it from Elmhurst Toyota. Create an account on supraforums.com and elmhurst toyota will give you a discount on all toyota and scion parts. The discount is a good percentage. They do this for all the supra owners, if they ask just say you also own a supra. If you guys have trouble let me know, I live close to Elmhurst Toyota and I would be glad to help.