I have a Sniper on my Challenger. It has a 511 stroker in it. The main issue I have had is RFI. The Terminator has a remote ECU that can be located away from the engine bay in a more friendly RFI environment.
That being said, I have gotten mine to run very well after cleaning up some wiring and changing to a Denso alternator.
I think the Terminator has more inputs and outputs that can be used.
Good luck, which ever way you go.

74 Challenger, bought it new. In 1978 I replaced the original 318 with a 446 and 727. Mild cam, Jardine headers, and Holley Sniper EFI.
New engine! 511" RB, Edelbrock Performer RPM heads, Eagle rotating assy, Comp hyd roller cam, Doug's 2" headers.