For me it is the optimal position. One of the main things I hate about iDrive is it's high location. I can't stand catching the screen out of the corner of my eye all the time, especially at night even if it's set to the dimmest setting. It also has voice, so once you have your destination set it will tell you when to turn so it's not necessary to look at the screen all the time. You can simply wait until it's safe and with the screen being 7" you can quickly glance and get the info you need from it safely. Also, as you can see the screen is slightly angled up. This is for two reasons, one because it had to fit under the heater vents, and two, it aims right at your face and makes it much easier to see.
Also, You have to look at the screen a lot less with this unit than you do iDrive because with the touch screen option it allows you to move through the menus much faster than iDrive does. It's also much simpler to use than iDrive.
One main reason I chose Eclipse is I had the previous version of this system in my last car and was used to it and really liked the way it worked. I considered some other options but without having any passed experience with them I decided to stick to what I know. The one thing that kinds sucks is the Eclipse won't read the phone book off my iPhone, not a big deal but would be cooler if it did. It will however read Blackberry phonebooks and many other phones too.