I think the eagle X is a bit more versatile and can do more lines, and is more forgiving if you accidentaly turn it over, as it will tend to come back better. With DX EX's and Star/champ EX's you can cover all your fairway driver shots. For me teebirds are good at going straight with a little fade, but they can't do to much else. A lot of people like DX TB's in stages of wear, but I think the DX TB get uncontrollably flippy pretty quick. The DX EX takes awhile to be really flippy, and will still fade back for a long time, allowing you to throw more lines. I have a DX EX I've had in my bag since june or so that has gotten almost daily use and hit plenty of trees, and it still isn't what I'd call flippy.
The teebird is probably a little longer on a straight line, but for me it might only be 10 feet or so... if that. I can personally throw my 175 star eagle X farther than the teebird on a big flex shot, sometimes to about 380 or so.