Pros: neautral sound, soundstage, great treble, great mids
Cons: bass can lack punch, poor sound isolation
DISCLAIMER: I am not an audiophile. I am an audio appreciator. I hope.
Overall I'd say that the value for these IEMs is pretty good, given how it sounds and what it does.
Highs - The highs for this is clear, crisp, and it sounds really good. It's not distorted at all no matter how much is going on, and the separation between the highs and mids is clean.
Mids - The mids are full and neutral. Its detailed without being flat, but there doesn't seem to be much coloration to it either.
Bass - It's there, but it's not in your face. If you are wanting "boom boom" or like to 'feel it' then these will be lacking in the bass department for you. That's not to say that the bass is missing, it's just not as present as in other IEMs. (Such as the Shure 535s.)
Soundstage - The soundstage sounds better than any other IEM I've heard. The soundstage for this sounds like a cross between the soundstage on the Sennheiser HD650 and the Byerdynamic T1. That is to say, it makes orchestral music sound great and reduces the feeling that you're just listening to noise, everything is clearly separated.
The IEM is light and easy to put in. It feels like the IEMs aren't even in my ear. The cord looks like cheep plastic, but its also very light and doesn't get in the way when you wear it. (I've not had any issues with the cord, its sturdy enough... just shiny plasticy black.)
I actually like the foam tips on these. They're more comfortable to me than Shures Olives. (Shures foam tips.) These are the second most comfortable IEMs I've worn... the first being Bose IE2. (So easy to put in!/wear!) They're light, comfortable, and sound great! The cord isn't that long, but it's the perfect length for DAP use.
It's "ok." but it doesn't block things out as much as I would think/like from an IEM that goes that far into your ear canal. It's not a big issue unless you want to use them in the subway or a noisy area.
The sound quality coupled with the comfort of wearing the Westone 4Rs is hard to beat. The biggest drawback is if you are looking for more "oomph" to your bass, with the second lesser drawback being the sound isolation. (Though you can always put Shure Olives onto these... its a bit of a mash-on, but they do fit. At least for me.)
If you want more omph to your bass and are willing to give up a -little- bit on high/mid/soundstage, think about the Shure 535s.