Maybe, AzNM, but I think that Porsche gets it right. In the Porsche design, the controls are small, but their placement and function makes them highly usable. Granted, in their sports cars at least (I can't remember what the Cayenne layout is), there is only one climate zone. Still, consider this:
In my experience of about two years of daily driving, the Porsche design is meant to be used purely by touch, with the driver's eyes where they should be, on the road. The temp and fan controls employ the same metaphor; nudge up to increment (higher temp or more fan), nudge down to decrement (lower temp or less fan). Yet they are far apart so you will never confuse them.
The Auto button and the three vent buttons are tiny, but each is so far apart from the other that once you learn that Auto is leftmost, then the sequence of the vent buttons (footwell, dash, windshield, left to right) you will never confuse them. Not shown in this photo is the recirculation button. It is located above this section and because of its position cannot be confused with the other climate controls.
In my experience of about seven months of daily driving, the BMW layout is designed to be visually elegant, but it cannot be easily used purely by touch. The main failure of the design is the bar of buttons in the center, Auto, fan and recirculation. Because these buttons form a plane and are all about the same size, it is easy to confuse them, especially the fan button.
Speaking of the fan button, I strongly disagree with BMW's decision to 1. make it a two-part button, but one unbroken surface, and 2. enable the left, decrement side of the button to cycle from "off" to "lowest". This 'soft toggle' design is probably intended to be a convenience, but I find it to be a classic over-optimization. Its effect is poor feedback to the driver, who when they are busy driving and want to just turn off the fan, does not need to get involved in a guessing game with the controls.
Other thoughts about this:
It may seem like a small thing, but we use these controls almost every time we drive. The degraded usability in the BMW design is one of the first things I noticed in the first weeks of owning my E90.
When I had my Boxster, someone once asked me what I liked best about it; at the time, I had owned it for only a month or so. I answered "The windshield wipers and the rear view mirror." He laughed, but he understood, saying "Yes, it can be the little things." One look in the mirrors of a modern Porsche (preferably not auto-dimming) and you'll see what I meant. The clarity is stunning.
My prior time spent riding BMW motorcycles taught me that with BMW, it's their way or the highway. When they get it into their heads that a certain thing should be done a certain way, no amount of complaint will force them to change it. So I'm not surprised to see the little design quirks in my E90, my first BMW car.
Luckily, in my E90 I spend about 99% of my time and attention exactly on the act of driving. BMW got the driving part very right. This is why I love the car and am quick to forgive its oddities.
Best,
Snaxster