VPX vs ACM
They are similar, as electronic breakers, but very different in other ways. I originally planned for the VPX Pro and even created schematics. Last week, I spent a bunch of time on the phone with ACS. Here's the major differences.
VPX
-Pro has a backup bus. Maybe important if the plane will be IFR
-Individual circuits can be used however you choose
ACS
-Plug and play for most of the Dynon or ACS avionics including switch modules. However, you still have to terminate the servos, ADAHRS and sticks.
-Built in ARINC for future addition if NAV/COM. They favor Avidyne
-Limited set of switch functions for the sticks
-Only one additional 5A circuit
I actually posted a spreadsheet to our group forum comparing the two systems financially. Very little difference in cost for the same equipment. I am leaning toward the ACM for ease of installation and maintenance. ACS will do the whole job including panel or you can order a "panel-less panel". The latter is tested and all the components shipped for your installation.
Also important. The ACM is not sold individually. It's part of a panel solution. You can use your own switches but it sort of defeats the purpose of plug and play.