EFI..Was it worth it??

For me it was. I'm all about "back yard" "low budget" and started playing with an old Holley Pro-jection system off CL for 75 bucks. Right after that, I found a Commander 950 TBI system for 375. Later I upgraded that system to the Holley HP ECU

I considered Megasquirt, and if I live long enough to get the Dart back together, I may play with a Megasquirt "just because."

The problems with older systems, including the Holley 950 and MS, is that they are not "self learning." The newer Holley stuff is, and the software you can get for the newer MS "makes" them self learning, at least my understanding.