Ive heard that ecu's with the 9L code have the best programming...is this true or are all ecu's about the same.

Whats the difference?

I am not to sure about the 9L code but basically all ECU's have the same identical format for which the engine to run on. But from time to time there is always a bulletin that comes out to repair a certain driveability issue and that's when the programming is changed. Many of todays new vehicles have the capabilities to be re-written for upgraded software in all areas. From engine management to transmission,ABS, and other area's, we now have the capability to download new parameters into ECU's time and time again.

Only ECU's with this re-writing feature can be altered. A basic stock ECU can also be changed somewhat with a piggyback system or a chip, but I believe they are limited. Alot of people with extensive mods are going to dyno shops and having a custom burnt ECU programmed for their particular application.
You can also do it yourself if you have a lap top or a PC with a software program and a ECU to play with.
Frank

The A9 "family" does have some advantages over some other ECUs, mostly more agressive timing curves.

The rest is basically the same.

A Custom chip or "tuner" like EECtuner, Tweecer, can change around 90% of the most important scalars and tables. So changing the ECU for another model/type is not a wise solution.

For a modified engine, a good custom chip or tuner is the way to go.