I can't see the pics. (Photobucket.com server appears to be down.) I'll look again in a while, since they sound like a good ones.
You're right, the extra 2 inches does not matter -- if you have high-enough wattage.
My tank is a bit of a forest and I have observed that growth is healthiest and most robust in the top 10 inches of its approx. 16 inch depth (factoring minimal substrate depth).
The problem is my Eclipse 3 hood, with its 40W bulbs at the very front, making the rear 2/3 of the tank darker than the front, in addition to the lower 6 inches being darker than the top 10. For people with 96W (or even 60W) this would definitely not be an issue.
My light variation is not at all visible to the eye, but the plants detect it for sure. Wisteria is my best indicator plant since it is the fastest growing.
When I bought it, the Wisteria was about 9 inches tall and grew to 15 inches, breaking the surface, in about 4 weeks. In early July I trimmed it to about 5 inches, putting it well within the lower "dark zone." Since then, it grew very slowly until it reached its current 10 inches in height. Now it has begun to noticeably accelerate.