Last weekend my father and I went to Mosport so I could pick up a part from 325isStephen and to meet MarkD so he could upload his tune onto my fathers M5. Mark was very nice and explained everything that he was doing to the car as he reprogrammed it. The car was supposed to have the Dinan stage 2 software to go with the CAI but the car recently got a software update from the dealer and whoever the tech was that did it he just over wrote the Dinan software, so the car was actually running stock software.... thanks BMW Waterloo. Mark informed us of this when he went to back up the software before uploading his. Needless to say since Dinan claims that their CAI + software is only good for a 5hp increase the change in software went unnoticed in a 400hp car. So anyways Mark uploaded his software with no problems and my father and I headed out. Now, I was in the car for the 2 hour drive both ways and on the way there we did a few hard pulls so I had a good idea of what the car felt like as a passenger. On the way back we did the same, and as a passenger I can say that the car pulled noticeably harder and my father confirmed this saying that the car felt stronger throughout the whole rev range (we never tested the whole rev range as my father rarely (if ever) takes his car to redline in any gear on the street
and with Mark's software the new rev limit is 7500 rpm
... I want to hear what 7500 rpm sounds like on an E39 M5
so I'm going to have to try and convince him to go for a drive in the country somewhere
or wait for the next track day he goes to). In addition to feeling stronger the car was much smoother on the overrun. The car use to really growl and vibrate on the overrun with the Dinan software, the OEM software from the dealer reduced the vibration, but with Mark's software it is much smoother now and has very little vibration, if any.
So take it for what it is, although I haven't witnessed the change in the car first person (i.e. as a driver), I witnessed it as a passenger... the car was definitely stronger, and according to may father the car drives much better now. After meeting and speaking with Mark about his product and his various projects I'd recommend him to anyone that is interested in a software/hardware upgrade. I'm going to be calling Mark again soon to get a chip for my M20