I stopped using midrange drivers a long time ago because the lower crossover point from the woofer to the midrange driver was in too critical a frequency range within the audio band, and was always too easy for me and others to hear as a discontinuity, and find distracting. I am a believer in the expression that "there is no crossover, like no crossover", but unfortunately every single full range driver that I have ever heard fell well short of expectations, and had too many discontinuities in the highs, nor enough bass - and ended up adding subwoofers crossed over fairly high plus add-on super-tweeters to sound OK - but the overall response of the full range driver was still quite bumpy.
Accordingly, in my own design work a compromise evolved. I began to use stereo subwoofers crossed over below 80Hz, which is a non-critical crossover point to the ear, and then I crossover the mid-woofer in the main speakers to the tweeter in the main speakers higher than normal at around 3.5KHz, which is again a better place for a crossover point. Not having any crossover point in the critical center band (80Hz to 3.5KHz) has been a great improvement in my opinion. Today there are an abundance of mid-woofers that I have found can cover this range very nicely.