Just got my w40 and listening to a few tracks and I must say wow! First of all the sound is rich and you can here everything that is going on from the vocals to the instruments. You can hear them individually instead of one combined sound. Everything sound crystal clear. One thing I find lacking is the sub bass. So far the only music that the phones dont do well is with hip hop or rap music with bass. Pop and jazz sound magnificient although i would like a little more bass.
The run down
Case is a lot better than the shure 425. Comes with a mini pelican like case with rubber seals.
Wires. The 425 wins this department in terms of quality. The connectors and wires are thicker and bigger and well made. The downside with the 425 is that it has a harder plastic wrap near the headphones which make the wires tougher to place behind the ear. The w40 wires are thinner and more flexible making this easier.
Build quality and plastic casing on the 425 seems to be better. The w40 plastic looks a little cheap.
The 425 casing is bigger than the w40 which makes the 425 less comfortable compared to the smaller w40.
The only thing lacking on the w40 is the sub bass, but everything else from the mid bass, mids, to highs are nice and smooth and balanced.
I am wondering if the w50 may be a better choice for hip hop because for that type of music i crave some nice sub bass.
Keep in mine that i returned the 425 under warranty so i am not shure if the sound was normal or if it was a defect.
Overall, for 500 the w40 seems to be little pricey since at that price i expect a total package in which the only thing lacking is the sub bass. I paid 399 after the 100 trade in so i guess its not a bad deal. At least i can say now that i have found a decent replacement for over the ear headphones.
Give me a few more days to play around with different ear pieces. I literally just pulled them out of the box and put them on with only 30 min of play.