I've had glass door type offices and cubicles... I think the cubes work better honestly, when I was part of a team supporting a very large server environment having everyone near each other and within speaking distance was great, but the cubes made it private enough so you could get work done without distraction. I prefer the 5' high cubes though, the little 3 or 4 footers are too low such that I always felt I was staring right at someone, or being watched myself, but the 6' or 7' walls were too high to stand up and talk over, 5' is just about right.