Great minds think alike. I'm using the very same Yamaha mixer and Carvin cabinets you are using. Just switched to the Yamaha mixer from a 6 channel Carvin, because the Carvin was mono and the Yamaha had two more channels.
I'm really happy with the combo. I have used a single three channel 100 watt Carvin, which is like using a powered cabinet and, like you, prefer the separate head and cabinets. If there is a problem with the cabinet or the PA head, you have options and back-ups.
I see no reason to change what we both are using. I frequently play outside for 500 plus people, and this rig, with the addition of a little Roland CM 30 for a pole mounted near field monitor works fine at the volume I work (sort of dinner background).
Of course, I have 6 or so jobs a year which require 6 1000 watt Crowns, 8 15's, 4 15" wedge monitors (powered by a 6000 watt head) and 4 18" subs.
Powered cabinets would not help much in those cases.
Be well. I'm keeping what I have.
R.