My mids feel weak to me too. I have MB Quart QSD 213's which are 5.25 comps. I think it is because the tweets are up high, while the mids are in the door poorly facing directly to the side, instead of being out and up a bit. I've already reduced the input to the tweets from the crossovers, then I mad some more success by adjusting the HPF high pass filter to allow a bit lower frequency through.
For my case, it might just be the nature of 5.25", paired with a 12 sub. I also like my sub volume up //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif