I've been listening to the Monster iSport Immersion earphones a lot since I received them and feel like I can make some impressions about their sound, comfort, and fit. As suspected, the bass and (to a lesser extent, the) treble have been boosted, making the midrange sound more recessed than it actually is. The thing with these earphones is that the midrange is there, it's just that the bass and treble are boosted so you have to play louder to hear the midrange clearly. I listen to mostly heavy metal, hip hop, and jazz. Metal doesn't sound too great on these; it's all guitar treble and bass drums, with the vocals kind of in the background. Hip hop sounds like it should, just with the bass boosted. Chopped and screwed music sounds great. Jazz sounds surprisingly good with good definition of the upright bass and horns. A problem is that the piano can sound muddy at the lower registers when it is combined with a kick drum. Otherwise, it's OK. The bass on these earphones isn't too boomy; it's more of an overabundance which can be distracting because it's so prominent. It's like Monster could have created a really awesome earphone with good all-around sound, but instead decided to boost the bass and treble for marketing purposes so they could write things like "great bass!" and "awesome clarity!" on the outside of the box because consumers don't know any better.
The most significant issue with these earphones is getting a good fit and seal. Getting a good seal is trickier with these earphones than any others that I have used and it can take a lot of adjusting to get them to fit properly in your ears. They come with five sizes of ear tips and ear clips which makes things better, but even when things are sized appropriately, it can still take some work. Once they are in your ears, they don't come out, but getting them in can be a challenge. Comfort is so-so. The ear clips press up against the top of a ridge in your ear so they are fine for an hour or so, but start to hurt after that. I had them in for a long plane ride from Washington D.C. back to Kiev, Ukraine and the ridge of my ears was hurting when I landed.
Build quality is not the greatest. They may be waterproof, but they look fragile to me. I thought that these had the metal construction of other Monster models, but no, it's just metal-colored plastic. I have no idea about their durability, but they don't look like they can withstand much abuse. I'll see what happens. The cord is flat which does a good job of reducing tangles and has a volume control / microphone on it for answering phone calls and such. Microphonics are definitely present, but given that my past reference are Westones that have virtually no microphonics, I don't know if the Monsters are above or below average in this regard.
Bottom line, these look like they will be a good choice for the gym, but are too colored to serve as a reference and too uncomfortable to be an everyday earphone. If I'm walking around town running errands, I'll reach for the Westones first. If I get a couple years out of the Monsters in the gym, I'll be happy with them.
One final note is not to pay anywhere near full retail price for these. Retail price is $180 for the set; I paid $130 at Amazon and that was the lowest price. At $180, it's a total ripoff; at $130, it's still a ripoff, but I don't feel like giving Westone any more money for earphones that break quickly.