The smell with the test pipes is a little more potent than with the cats when started in my garage with the doors cracked. Not terrible but you can notice it.
I am sure when it is outside it will not be bad.
I would comment on sound change if I had mufflers on the car right now...
UPDATE: Put the mufflers back on and the test pipes do not change much when driving normally. No drone with the Dinan setup that I can tell. They do have more rasp when you give it the happy pedal