When is it worth it to upgrade from the first Gen port EFI Edelbrock to say the newest 4 version. Seems biggest change is sequential vs batch. Not sure what other useful bells and whistles are really needed/worthwhile. I suspect if Edelbrock will piece meal the upgrade, its mainly ECU, Dual sync Dist, wiring harness, controller, and manifold, injectors, fuel supply stays the same?
My application is non race, street performance only.

Little to no advantage to you if your system is dialed in. Sequential gets you a little more precise fuel control which the OEM uses more for emissions control and getting that last tenth of a MPG for their CAFE ratings than any meaningful power increase.

Kevin

My buddy recently installed the Pro-Flo 4 on his 440. The main reported advantage is the nicely updated programing. They really upgraded how well the system self learns and adapts to ongoing operations. It's reportedly levels above their Pro-Flo 3 set-up.

As mentioned in the first response though, if your system is really well dialed in, there will be little noticeable difference. The main difference between the two should be the amount of tuning you had to do manually to get your current system dialed in, especially hot start and the more complicated tuning issues. Where as the Pro-Flo 4 pretty much does all that tuning using its self learning and more refined initial set-up tables and strategies.