I personally did not like the SM3 at all, but I am not sure if it was the v2 that I sold or not. How can you tell the difference between the v1 and v2? Also, I would not make a purchase based off of one person's impressions between IEMs. Find some reputable comparisons between the SM3 and W4 and make an informed decision.
I'm not sure about the difference between two versions, but I didn't see much comparison reviews for them.