I have couple mates working in speed/service shop, and that's what they say also.It is not worth it! Instead of paying for an ecu remap, spend the cash for a good service...uncluding spark plugs, fuel filter, a good quality synthetic oil.
Then fill the gas tank with a good quality high octane gas.
Last increase the air quantity that goes in your engine so that it breathes easier. A good dry panel filter like pipercross or hks would do.
There you go! Now your engine is more healthy, and with the vanos advancing you wil feel the difference in power!
They're mostly dealing with Mercedes and Porsche, but anyway... chip tuning is quite useless without forced induction.