I started out by looking for some performance enhancements in my 97 528i doing the usual K&N air filter addition. Next I ordered a Conforti software upgrade for my "5" and my 2002 330i. The software was a complete waste of my time and I felt sorry for the poor service station (it only services BMW's) that tried to install it. Its my belief that the Software packages were both a bust.

ghead He tried installing on the "5" the Conforti stuff and it wouldn't take, getting a 123 code - low voltage. I bought a new battery - which it turns out I didn't need - and we hooked it up to a charger, after the original 123 code. Then we turned off the heated mirrors, disconnected the Canadian running lights and all the fuses as required by directions on the package. We did this to both the "5" and the "3". In neither case would they take, always giving a code 123. What was interesting was that on the "3", the software is different, and just to make sure it wasn't an error with the charger, we tried another charger - still wouldn't take.

used
I went to one of the BMW dealerships here in Vancouver (Richmond actually) as they are a Dinan distributor. I had them install the Dina software for an improvement in engine tuning. I have to say I was skeptical of how effective this software upgrade would be. But as soon as I got the car back and stepped on the accelerator I noticed a more dramatic leap forward than before. I don't know what it adjusted at the lower end, but it definitely gave some more lower end grunt.

I noticed they are offering a driveline tuning package, a software package to "make the driveline more efficient in order to take full advante of the engines's new found power (from the other software upgrade) for even faster acceleration."
I think I will try this next. I will say I was disappointed at the poor quality of the Conforti items - they will be returned. I would have prefered them as you keep the software installer whereas in the Dina dealer install, you don't have any installer to keep; if I lose the program I have to pay for a new program in the Dinan deal.
If you have a late 90's 528i, I can recommend the Dinan upgrade to your software.