I am a huge proponent of kick panel installs. There are some reasons they are not as popular anymore. One is that fact that many new cars have little actual space in the kicks, and the space that is there is usually occupied by wiring and numerous electronic boxes. Another is that modern cars have very deep dashes, windshields that stretch further out onto the nose of the car, and large sail panels, all of which facilitate placement of drivers. But the main culprit is near ubiquitous DSP with the addition of multiple inexpensive amp channels.
However, I personally have issues with all the phantom sources typical of dash and pillar installs. They sound good initially, but my ears can't handle the chaos even when things measure well. With kick panels, I can usually get good tonality and imaging with angle and placement alone. I also find that the individual drivers blend and "disappear" much better with kicks.
These things are very car dependent though. In my BMW E34, I literally had 3-ways in the kicks, with 8" midbass, with all acoustic centers aligned by placement and angle of the individual drivers alone.
In my current project, the midbass is in the doors with mids in the kicks. But the mids will reach fairly high in freq. I have some small AMT that I may use for the last 1 to 1.5 octaves at the corner of the dash. But the AMT might end up in the kicks (just depends). Although this car is not as blessed as the E34, I am pretty tall, and I naturally sit pretty far back, which makes a difference. Because of this, I have also found that high frequency response is not blocked too severely by my legs. Driver placement is no where near my feet in a way that will block anything.