You may want to note that some people have fit issues with the TF10s, I personally never did when using Complys. The TF10s have a sort of V-shaped sound signature, where there is more emphasis on the treble and bass, and some consider the mids to be recessed. I did find the mids on the TF10 lacking for some songs, but the TF10s have a very fun sound that I can't see many people disliking. The soundstage on the TF10 is also very spacious amongst the 3-driver IEMs. However, be prepared to spend another 50-150 dollars on an aftermarket/custom cable for the TF10s, as the stock cable on it is simply ATROCIOUS. The memory wire (the part that is sort of stiff to form a shape around your ear) is extremely stiff, and coiling up the IEMs and putting them in your pocket makes the memory effect extremely annoying, as it will be uncomfortable to wear and, if angled in a certain way, will push the IEMs out of your ear or cause you to get a poor fit. The stock cable actually broke after about 2-3 months of daily use. There are some very good aftermarket cables available, I would personally recommend the Lune/Arete series of cables, or the Beat Audio cables if you have a larger budget. I have tried many different cables on the TF10, and I could instantly tell that there were clearly audible differences between the stock cable and the aftermarket cables.
The SM3s (v1) feel very fragile due to the plastic that is used to house them, and the design of the housing may make putting them in your ears uncomfortable for long periods of usage because the end of the housing will rub against your ear. The SM3v2 fixes this by having a new opaque plastic housing that feels more sturdy. The SM3s are also touted to be very "chameleon" sounding, meaning that they accurately reproduce music as true as it can. However, some of the people I know who have owned SM3s say that the treble is slightly lacking, and that it was a mid centered IEM.
I have not tried the Westone 4 for a very long period as Westone IEMs, for some reason, don't fit in my ears very well :P I would recommend you trying each of them out before you buy them, as always, since despite what reviews may say, what matters most is what YOU hear. ;)