The Evolve 4 has a roughly 9" x 9" front panel. The Evolve 8 has a roughly 12" x 12" front panel. That puts it about 44% bigger
B for sure
This subject was addressed by RTR years ago. Along with the minute volume added to the tank which dilutes the chlorine concentration , the chlorine quickly
The proportions are beautiful. Good choice. Very classy and big without being overpowering.
I have a 130 with an open top (plenty of natural evaporation). The water flows through 12' of planted trough (I'm pretty sure you have commented on pics