Having owned the Momo's and the DB's I went again with the Db's. Same can be said for the new MM's after hearing them as well It's not necessarily one is better, its just that the 2 Polk speakers sound so much different when powered correctly.
The Momo's and now revamped MM's give the most truest sound if you ask me. They pump out good mids,highs, and lows especially in open air. They give you the most complete/truest sound. Great if you don't plan on adding a sub. Some people actually prefer them even with a sub. I just do not......just my opinion
The Db's give you a much more crisp sound. You lose a little thump of the lows and some of the mids compared to the Momo's, but I actually prefer that as I have a dedicated sub to give me what the Db's don't. However again I prefer the Db's clarity. The other bonus is the Db's don't require as much power to get loud and clear.
The Kickers. while I am a huge fan of their amps just don't really like the sound of their mid range speakers. Seems you always hae to go to their top of the line product to get a sound that I prefer. I have zero experience with the KM line so really can't give you an honest opinion.
Current: 2008 Super Air 210TE
Previous : 2000 X-Star, 3000lbs ballast, LTR 330, Acme 1235 14.5X14.25prop. 1200 hrs of flawless fun