Check my Evolve exhaust thread if you didn't already. The very reason why I love this exhaust is it really is very refined and civilized when you don't push the throttle and it is really loud and killer when you want to get things heat up, especially after around 4000 rpm. It is the real Dr. Jekyll and Mr. Hyde exhaust (without a button or so managing that) which I was looking for and it keeps on getting better with every mile.
There are small pops and burbles all around the range, cold start is awsome and loud and drone is infinitely better than the stock, both in intensity and range, I don't even count it as an issue anymore. I had a huge drone between 2000 to 2900 rpm with stock.
It also doesn't get that metallic raspy sound at the top end of the acceleration like some other exhausts do. I love some other exhaust sounds as well (Lightweight, Meisterscaft etc.) but for the price this just seems to be flawless imo. I wouldn't change it to anything, louder or not.
2011 BMW 1M: Euro spec, w/out Nav, manual seats. Evolve Race+N55 mid, Michelin PSS, ER charge pipe, aFe ProDryS drop-in filter, CDVx, BMW-IND trunk spoiler matt cf/VO stripe, BMW blacklines, BMW black grills, IND side gills&rear M logo, silver turn indicator bulbs, anthrazit overlays on side creases and on air curtains, MPerformance steering wheel w/VO ring, BMW steel pedals, custom mats, color matched MPower e-brake.