Jeff, you have a PM.
Each and every system that runs in speed density mode (relies on the MAP sensor for engine load calculations) will require that the ECU be mapped for your particular engine. Doesn't matter who makes it, what start up map it comes with, how advanced it is, or how much it costs. Speed density requires that the ECU know the VE curve of the engine. It then uses manifold pressure (MAP) and RPM (among other sensors) to calculate fuel requirements. Some systems have an actual VE table. Others, like the Haltech, do not but the operating system is calculating the information in the back ground. Since VE will be different between each and every engine regardless of whether they roll off the assembly line side-by-side each engine will need to have it's ECU calibrated for itself and itself alone to ensure optimum operation. No way around that.
Systems that are MAF based can be generic from engine to engine since the MAF sensor is calculating the actual mass of air entering the engine (not interpolating it based on manifold pressure and RPM as in a speed density system) at any given moment and fuel is calculated according to this exact measurement. If VE is different between engines the MAF sensor sees this and the amount of fuel is corrected to maintain the desired mixture. Unfortunately, most systems of the aftermarket only operate in speed density mode.
Haltech and other higher end systems do have the option to run in MAF mode. The only downside in an Improved Touring situation is that calibration can be more time consuming. The aftermarket has not embraced MAF sensors in performance applications because they are generally viewed as a bottle neck to performance and can provide inconsistent results when the intake tract around them is altered or they are asked to flow much beyond the mass of air they are engineered to support from the factory. There are few shops that have much experience at all with performance tuning and MAF sensors. Those that do are centered around the GM and Ford V8 market.
And as Chuck pointed out most every system on the market has the ability to compensate for atmospheric conditions. The beauty of atmospheric compensation is that it is largely a mathematic constant. Meaning that it's not a feature that needs much tuning though most system have the ability to tweak the response to atmospheric change. In short this isn't a carburator and should not require the end user to pull the laptop out when a cloud rolls overhead. To the contrary one of EFI's main advantages is that it can provide optimum performance under widely varying atmospheric conditions.
With that said, a few words of advice to anyone considering a system of any kind...
1) There is no such thing as a plug-n-play map for a speed density system that can be guaranteed as optimum. You may get lucky and get very close but beware of anyone that says you can plug it in and go and expect it to be perfect. "Start up" or "base" maps are just that. To expand on that anything that changes the VE of the engine will require a corresponding change to the calibration. Since the engine doesn't know you changes VE you will be lean or rich of optimum when you make changes to the exhaust or intake that enhances or degrades airflow through the engine. After you have fitted your speed density system to your engine and calibrated it you will need to make tweaks to the calibration to see if that new exhaust really has netted more power. A rule of thumb is that if you make changes and the mixture leans out in any particular spot of the rev range then you have increased airflow there and there is potential for more power. The inverse is true. Further, optimum tune is fuel dependent. This gets off into a tangent on engine tuning but illustrates my point that it's almost impossible to have a generic optimum tune. Ignition timing requirements can vary depending on the fuel used while still producing very close power outputs.
2) To get the most out of any of these systems you need dyno time. The dyno is the only place that provides the controlled environment needed for optimization of fuel and even more so for spark. Plan this into your budget. With a good game plan a good tuner can calibrate an engine from scratch in 2-6 hours so it's not a totally bank breaking proposition.
3) Also, and it's been mentioned before, you'll need a wideband. Good dyno shops have them and it should be part of the package when using their dyno. It's better to have one of your own and have logging capability. Not all widebands are created equally and response time and consistency separates the good from the bad. Knock sensors, det cans, EGT logging, etc. all come in handy when trying to nail down the optimum tune as well but that's all for another thread. Wideband shootout....
http://www.fordmuscle.com/archives/2007/06...otout/index.php