Shure SE215 vs Jaybird X3

Bass is emphasized so there is a good bit of thump while staying controlled. Mids are rich, highs avoid sibilance, though they're a bit rolled off.
Soundstage is okay--instruments are separated out enough for them to not sound like they're all coming from the same place, but it's not particularly wide.

The memory foam eartips mold to your ear to provide amazing sound isolation, though there's a bit of a learning curve to using them. You have to press them together before putting them in and then allow them to expand in your ear. Once expanded they will take the shape of your ear and that way provide excellent noise isolation.

The earphones also come with silicon tips which are easier to use than the foam ones and also last longer.

The SE215 earphones have a negative profile, optimized nozzle angle, over-ear fit and memory eartips that ensure the earphones stay in place comfortably regardless of situation. You can even lie on your side with them.

6 types of plugs (silicon/ foam: S/M/L).

SE215 earbuds use tough plastic earpiece shells, have a robust kevlar-reinforced cable, a sturdy Y-splitter that's difficult to bend and an L-shaped plug that adds additional strain relief. They won't break if you snag them, drop them or sit on them. They're also completely sweat proof so you can use them while working out without having to worry about damaging them. They're durable enough for professional stage use for which they were specifically designed for.

The SE215's 6.4-ft. cable is very thick, and further reinforced at the left/right split point. Reviews confirm the durability benefits of its heavy-duty design. If it ever does break, the cable is built to detach safely from the earpieces, allowing replacement.

The optimized angle of the earbuds, over-ear fit, and memory ear tips ensure that the earphones stay in place comfortably regardless of situation. These are also sweat-proof, so they're a great option for active use.

Shure provides a warranty against defects in materials or manufacturing for two years.

Exposure to splashes of rain or sweat won't easily damage these earphones.

The highs are crisp, airy and forward so detail presentation is very good. Bass is fast and controlled instead of boomy, so it does not muddy up the overall sound. The mids sound natural and do not get lost in the mix.
This sound signature works well with a wide range of genres and rock, pop, hip-hop and EDM will definitely sound great with these headphones.

The X3 comes with wing tips that you can attach to the earpieces. The tips enhance the grip of the headphones in the ear, and will help keep them secure even while you are running

The in-line remote will allow you to control music playback, adjust volume as well as answer/end calls.

Integrated into the remote is a microphone, so you do not need to pull out your phone should a call come in. Mic quality is pretty decent, and your voice should be easy to understand on the other line.

You get standard silicone ear tips in different sizes, along with a carrying case, different sized wing tips, premium Comply foam ear tips in different sizes, cable management clips as well as the charging cradle with micro-USB cable.

The older X2 model had bigger and heavier earpieces which made them prone to falling off, and also made it difficult to use the earphones with a helmet or a hat. The X3’s earpieces have been redesigned to be smaller, while the internal batteries have been moved from the earpiece to the remote. This helps keep the X3 in-place inside the ears and at the same time makes these earphones easier to fit under a hat or helmet.

The X3 gets around 8 hours of playback time from a full charge. This battery life is much more consistent compared to the previous model which had spotty battery life.

Signal quality is pretty stable with minimal distortion or drops, even if you are on the move.