My thoughts on this: (for whatever they are worth haha)
-Traditional: great original ties that look great when tied properly, but that's the issue often. I see a lot of sloppily tied ones out there and I don't claim to have mastered the art of it by any stretch of the imagination. I have always interviewed in these however.
-Zipper: darn near good enough to make me wonder why they still make other ties. There is almost no downside I can see to the zipper tie. Looks like a properly tied tie without the "clip-on dimple." Every airline should offer this option. I got married in one that came with the suit and it looked great.
-Clip-on: I hear arguments for these from pilots that are around belt-loaders and are concerned about security threats (getting grabbed by the tie), which I suppose are valid. However, they look tacky. Period. I can tell when people wear them and it seems like the lazy solution. However, I have worn them too so no judging on my part, just noting that they aren't my preference.