Different Carb or EFI

I have run the old Holley Pro-jection TBI for 20 years on my Newport. It requires constant tweaking, even with O2 feedback, especially their smaller 2Di box. Their follow on Commander 950 is supposed to be much better, with more sensors (MAP, IAT) and more tuneability. I will try on several cars when I have time. It can control TBI or MPFI, plus spark. A used system usually ~$600 on ebay, though I got an ECU alone for $125. The Avenger is Holley's latest, but ~$2000. Looks like mostly a slicker interface. Many people seem to buy systems and give up, sometimes without even trying. Makes a cheap resale market for guys like me that are resourceful but cheap.