Pros: Fun, thick, musical sound, good timbre, good build quality
Cons: Isolation is only average
When I went looking for a new IEM last year, I really did a lot of research and wanted something with great SQ and detail but also fun sounding as I listen to a lot of rock and planned to use this pair at the gym.
These are an absolutely fantastic value. They can be had for around 80-90 bucks online, and for that price they are absolutely wonderful IEMs. Check out the excellent review here on Head-Fi in the 309 IEM comparison thread for a more detailed review of these.
These are not analytical phones by any means, but they provide very good detail and imaging, excellent timbre, and are flat out fun to listen to. Not a basshead IEM, but the bass does have good impact and authority. The presentation is very intimate and somewhat in your face, but I liked that aspect of them for what I was using them for. They have good energy and kept me pumped during my workouts.
The somewhat U-shaped frequency range of these makes them excellent for rock, which is mostly what I listen to, but they work well with other genres as well.
Isolation is okay but not great, but that's to be expected given their design and relatively shallow insertion. They are pretty comfortable, but not the most comfortable IEM I've used. Build quality is very sturdy with a semi-translucent shell that lets you see the two carbon nanotube drivers inside. They are tough little drivers and do take a bit of a burn in period to loosen them up. Mine didn't start to sound their best until after a couple months of use.
Sadly someone stole them last month, and I ended up trying a HiFiMan Re-400 as a replacement, but I would highly recommend them, especially to rock fans, and I definitely may pick up a pair again down the road.