I'm with the majority of the people who like this system. I have the same system in my e39, and I also have the settings "tweaked" from the excerpt I posted. We have too many cold days, and when it gets warm, I like to drive with open windows...to enjoy.

So I use the A/C very seldom, basically in both my vehicles with this same HVAC system, I use the above settings minus the A/C (only in very rare occasions as I said). The center dash dial I have it set in the middle most of the time, but I noticed it doesn't really matter. If the dial is set to hot, and the cabin gets toasty, the vents will start blowing cold air anyways. Vice-versa doesn't work. At least on my e39, that's how it works. The e53 I set it up just like the e39, and I have absolutely no problems.