I have heard the W4R, and I'm going to just put it out there curtly and say you're just too used to too much treble, and not an overall balanced sound. It's either that, or your fit is bad. Most honest unbiased people with a reasonable amount of experience with many other high-end headphones, IEM or full sized, will tell you that W4/R does NOT sound as if it's the best sounding thing out there, like what the reviews here on head-fi suggest. I see reviews filled with glorious accolade, "liquid mids," "outstanding detail," etc. etc. which quite successfully enrages me; it's almost as bad as cable reviews making it seem like they make a complete night and day difference, as if the sonic signature was completely altered to cater their needs. Exaggeration at its finest. I'm willing to bet all this is because of some sort of need to self-justify purchases, or just to reap Head-Fi karma. This is why you see complete polar opposite reviews and impressions of the W4/R.
No offense intended. My rant is directed towards the general Head-Fi public.
Here are two examples. Two Headphoneus Supremuses who have no reasons or intensions to falsely claim anything. Read through the thread. You'll find a pattern: most people trying to convince them that W4 is not as bad as they hear it is say to 1. give it more time, 2. burn it in, 3. get used to the sound. One Headphoneus Supremus tells the guy to give it more time to grow on him; if you look at his gear list, and his system, you'll probably understand why he's telling him this BS. Anyone can get used to any sound, and at some point that will become their reference point... However, we're talking about actual inherently superior sound.
http://www.head-fi.org/t/570821/westone-4-disappointment#post_7739257
http://www.head-fi.org/t/570821/westone-4-disappointment/15#post_7740034
One thing I might add is that I did find the ES5 a bit muffled up top. I fixed that with an inherently transparent, non-coloring, cable. I do not prefer to change the tuned signature I paid $1000 for with external factors like amps and EQ. In your case, Westone's stock cable is a piece of garbage, in my opinion. Burn in is really not needed for the ES5, I didn't notice a change at all.