For me, none of the short tips work, not the Complys or the olives or the gray silicones. I need at a minimum the bi-flanges. I have a messed up ear situation, whereby my right ear does not seal as easily as the left (my customs really show it). So I need deep tips with Westone phones, because they are not like Etys or other phones that can be sunk in there.
Having said that, apart from the UM56s, the modded bi-flanges/tri-flanges (stalk trimmed), the large Comply and, I still have the original Comply thins that came with my W3, and they also provide an excellent seal and allow the bass to make it to my eardrums.
Anyway, I really do like the W2 signature, more than the UM3X for my tastes and while it may not be as thrilling as the W3, I think for $100+ less, it works for me. I can't believe how small the driver housing is, and comfy they are. Just what I was looking for in a second high-end IEM, apart from the TF10s I have on hand. I will wait for tomorrow to do the comparison listening with the Trips, but I think both will have a place here.
Best thing is while there is some hiss with the Amp3s, it's nowhere near as bad as the UM3X and the synergy is on the money. Raul Malo never sounded cleaner and clearer, at least not through an IEM on the Amp3.