Go to Jaben at Adelphi and audition both of these sets. There is an enormous difference between the sound as far as I'm concerned. The Westone 3 is way way more heavy on the lows. For me, the TF10 just didn't have enough punch in the bass. In fact I was surprised that it didn't sound much better than my UE700s.
I also have to agree with the other poster. The W3 fits in my ear perfectly, and I think I could wear it all day or on a long flight no problem. The TF10s are just weird. They stick out of my ear about a mile.