This morning I ordered the Really Right Stuff TFC-34 Mark II tripod that Vieri recommended, this decision was different than what I had expected when I started this post. Based on much of the feedback, I was afraid that a travel tripod was not going to meet my needs, so then my search changed to what was the best all around solution for my needs. The RRS TFC-34 was my conclusion/compromise, it is almost 0.65lbs lighter than my Gitzo GT3533LS and has a folded length that is about 5.5 inches shorter. In addition to that, when needed, I can shave another 1.15lbs off of that by switching from my D4 head to my P0. Now to your questions.
HEIGHT: preferable in the 50-60", I would say most often my tripod height when shooting is 48" or lower.
Center column needed, OK, or not OK? I never use a center column.
WEIGHT: I had hoped to stay under 3lbs, in the end I did not, I came in at 3.85lbs
COMPACTNESS: My current tripod with the D4 head on it is nearly 31", at times this left me feeling a bit top heavy. The RRS TFC-34 will be approximately 25" with the D4, I hope this helps with that issue.
USE: I shoot automobiles, architecture and here my current setup was great. I also hike with my pack, typically never more than 10miles round trip, here is where I have been trying to shave weight. I find significant elevation changes or sand to be where I really suffer. I have gone from a backpack weight of just over 31 lbs to my current weight of 25.5 lbs. I am hoping that makes a big difference.
Good luck in your tripod journey!