Hey guys I actually put the Eisenmann race exhaust with the 3.5 inch tips on my 2014 335 MSport. I can tell you right now it sounds amazing! I didn't swap out the downpipes and I can tell you it is still a huge upgrade in sound. The low RPM burble sounds awesome. I find myself def driving in sport + mode alot more haha. My buddy and I took a great video of what it sounds like at low and hig RPMS. Below is a link to the video on youtube.
http://youtub.be/w1PGS8eRQRQ