Exactly, sequencial injection isn't needed for a street performance engine. Maybe on a GTP car that needs to individually tune the fuel mixture on each cylinder this type of control is needed? Batch/gang fire works fine.
Same with ditributorless ignition, I just don't see the -big- advanatge unless you have an individual coil on plug setup that eliminates the wires too.
My sugestion on EFI managment systems is to look at the software and decide from that. Ease of tuning makes or breaks a stand alone EFI system and is the main advantage with SDS. The only windows based system I'd be interested in using is the haltech. YMMV
Also when you are comparing prices, include EVERYTHING it's going to take to have a running car and maybe the time involved as well unless you consider your time worth nothing, I don't! A -box- with no harness, sensors, connectors etc is far from a complete system.