I have definitly thought about downsizing. The stock size is 1.75" and I've thought about 1.5". The problem is finding components that are that small. If I could find a 1.5" in/out CAT, resonator (or glasspack muffler) and muffler I'd consider it. Even finding straight SS pipe and mandrel bends in that size can be difficult. I'd rather not have to deal with a ton of adapters (1.5 -> 1.75) just to piece the thing together either.
Keep the suggestions comming though!