Looking good and looks like your on top of the
maintenance. Exhausts a really difficult / personal thing. I would say mine is quiet (full Milltek - resonated). But when I visit my mom she takes my dinner out the oven when I'm about 3/4 mile away (it's a quiet housing estate). The decat and downpipe will make it louder, as will choosing a non resonated catback (and also cheaper).
Scorpion might be worth a look as well as Trackslag which I'm debating switching over to. BCS are also quite highly regarded. I've not heard of Cobra before, but a quick Google seems quite positive. I won't be getting another Milltek... and a think there are a fair number of people who won't be either.