Hey David,
You are correct. It all comes down to personal preference and $$$ mostly, but here's my 2c. I prefer over hear because it's more comfortable for me and inner ear phones don't stay in my ears (I must have weird ears). Looks don't mean squat to me. I only care about quality of the sound and the build. I have a set of Audio Technica M50x and V-Moda Crossfader M100s. Neither are noise cancelling, but are very comfy and awesome quality.
Noise cancelling phones I've had experience with are only Plantronics back beat pro. Mates have these and they are quite good. In a plane, the whirring is reduced to white noise fairly well. Definitely doesn't TOTALLY reduce all outside noise (depending on how loud it is), but they are quite good.
Besides online reviews, the best thing you can do is get to a store and try them on.
Everyone's ears are different.