Actually I wonder if there is any merit to chosing one management over another.
Personally, I think it's highlydependent on the features you're planning to use.
For me, I'm using the hondata s300, but if I have the money, it'll probably be AEM EMS with the Engine Position Sensor, so I can run coil packs and ditch the distributor and plug wires. There are loads of other inputs and outputs too, but it would take ages to do them all. To make the car run, probably quite easy. To implement ALL the features the ECU has into an old-bseries engine? probably not so easy.
There's also features that are available that usually don't get used, like strain gauge, g-sensors, compensation, ign. retard per (insert factor here).
For me, a full standalone that is hassle free and very easy to use is hondata. No fiddling through long forums or having zero tech support. Most of the time, its so easy, you can adjust the more important settings yourself, like idle speed, or in some cases, idle valve duty, and identifying CEL codes and resetting CEL without removing battery and more.
For me, the most useful is datalog. Datalog is most useful when trouble shooting intermittent (aka sometime got, sometime don't have) problems. For example, do you have any idea how to track down an intermittently faulty TPS? Naturally TPS don't spoil, but in my case, my car jerked on light throttle for a day then disappeared, then occured again, I datalogged, found that the TPS signal is erratic, and sometimes voltage dropped, engaging the DFCO (discrete fuel cutoff, a normal feature in most Japanese EFI cars for fuel economy.) causing the jerk.
Easy, problem solved.
Otherwise, I'd have checked the plugs, the plug cables, the distributor coil, etc. etc. which takes ages, not to mention having to replace parts that is possibly faulty (halfcut yard)
Normally, we'd have checked the plugs, the plug cables, the distributor, etc, but with datalogging, can actually cut down diagnostic time, if the owner/owner's mechanic/tuner knows how to tinker with it, or already suspects a problem, but cannot see it for himself.
Depending on use, you can do a lot of things with a standalone. Since I run the
hondata-innovate LM1+auxbox combo, for me, the features are quite enough, though I'd still want coilpacks so can ditch the distributor + plugwires.
Features I use:
a) G-sensors for two directions (front/rear & left/right) Very useful to set your suspension hardness. You can actually see the difference in the amount of 'tilt' you car has with different settings.
b) o2 sensor : Very useful to check for fuelling problems. Engine choking? injector possibly dirty? running dangerously lean? Fuel pump maxing out?
c) injector duty through innovate LMA-3 (much more accurate, hondata, and most other after market ECUs) displays 'uncorrected' duty. Fuelling changes based on IAT/ECT and barometric/PA sensor (on some cars), so what appears on the map versus what innovate reads off the injector is not the same.
d) Oil press - with a 5V pressure sensor, the LM1 can read oil pressure sensors. They're not cheap though, so a 300 or so mechanical oil temp would do a better job and cheaper too. It's so you know when you're losing oil pressure (which usually indicates a failing/failed oil pump) so you can replace it before major damage happen.
e) video output - if you're into racing (legal or ahem! otherwise), but pls remember ZTH does not condone/support illegal racing).
In hondata s300, there is a little known feature that can output engine parameters so you can overlay them on video. No more do you need to take picture of meter or whatever. Just datalog, and when editing your in-car cam, overlay it on the video to get real time engine parameter feedback on the video. I already posted the link many times before, so I won't whore it again.
In the end, the ECU choice must best reflect what you want to do. If you want the bases of features, it's crome for honda. Hondata s300 pluses are the friendlier software and support, and also the fact that it comes with a built in ROM emulator. No mess of fiddly cables.. just a board, and a RM5 USB cable, and since it's so easy, heck, even the owner can do some of the settings himself (though not for ALL settings)
For me, if considering to run a VERY expensive standalone, it's best done with an individual coil packs conversion for it to be truly value for money / for it to make sense. Or with AEM EMS's standalone, I'd love to play with the traction control and various other inputs and outputs.
more expensive does not equate better in some cases. like the F-Con V pro. IT's not a lousy ECU, I think it's a great system with drive by wire support, but the price... (O_o) Not forgetting, that FCON-V pro is a street ECU, with provisions to retain the original ECU for climate control.
Many plusses and minuses to each brand. It's up to the owner to see how deep his pocket goes, and how much CONTROL(tuning wise) he wants over his car.