Pros: Price!!!, Mids, crisp & clear sound, isolation, design, no hissing
Cons: At this price, nothing really.
The sound in general is quite sparkling, open and well balanced for a single driver IEM.
The first thing i notice is that the bass is a little flat and lacks a bit of depth compared to high-end multi-driver IEM's. It doesn't have that good punch, warmth or layered experience most high-end IEM's possess.
Update: the bass does seem to be better now, could also because of a better fit i've found.
Once the music evolves to more complex compositions it's losing it's composure and that's were you notice most these are $30 headphones.
But listening to more mid centered music (singer songwriter stuff etc) is where these LG's shine. It's open,crisp and clear without getting harsh highs.
It's the area most of these cheaper IEM's get either harsh or veiled, but the LG's are great for this.
The soundstage is ok, not very wide, but natural sounding, it lacks depth and layers though. It just lacks some involvement in presentation. It's clear, but somehow just out of reach. The sound comes from a few meters away, where good high-end phones create much more intensity where you feel you can touch the music.
The comfort isn't great for me with the supplied tips. They irritate quite quickly. But you can fix that with comply tips for instance.
Update: tried with smaller tips then i usually do and now the fit quite well. Light irritation, but something i can easily wear for a few hours.
The design is pretty good. The way they shape in your ear gives a very good seal. They do stick out slightly, which i don't prefer, but most IEM's have this issue. And they look nice too. The flat cord looks solid enough without losing flexibility.
Isolation is superb and works very well, considering i usually user custom tips for my #1 IEM, the Audeo PFE-232's.
All in all, the positioning, experience and presentation is pretty darn good considering the price. They are open, but don't get harsh and therefore have a laidback sound without losing it's timings which is easy to listen too.
For me it's the lows that are the weaker part with these QB2's. They have something veiled over them and lack real depth and low frequencies, making them sound a little dull. It just lacks the real timbre and quality of instruments the high-end phones deliver. But then i'm talking about multidriver €400 - 500 headphones, so there's no way you can compare these.
Although in some areas they come quite close to my Shure SE535's, which says something. Actually, i prefer listening to these ;-) The Shure's are too harsh for my taste.
Comparing it to my Phonak PFE-232's it really becomes very clear though. That's a no contest. It's not in the same level.
For the price a no brainer if you're on a budget. For me it's a nice backup IEM for emergency's :)