I felt all of the speakers were nicer quality than the HK ones I removed. However, I have been having some issues that I suspect are more in the amp and/or head unit, and finally have Jason at BSW providing some tech support to troubleshoot.
One of the challenges with going MBQ or other aftermarket is getting the right impedances to work properly with the factory amp. BMW has complicated things by having all of the crossover action happen in the amp, so to go aftermarket in most cases will mean replacing the amp, speakers, and wiring in a different way (may be able use the factory wiring, but likely only one pair to each channel and then crossed over at the speaker rather than in the amp).
orange260z
2009 Porsche Carrera S Coupe PDK/Sport Chrono Plus - Porsche Racing Green / Sand Beige Full Leather
1999 Miata - Brilliant Black/Tan Leather