Pros: Balance, lovely bass, lightweight. They sound lovely and have 2 years warranty.
Cons: Accessories pretty bare bones.
Only short review from me.
Since the "The Wirecutter" claimed these would be the best IEMs under $100 I had to try them when I saw them for $49 on a very special sale.
They are fantastic allrounders, the bass is pronounced a tad bloated maybe, but pleasurable to listen to, clarity, pretty decent miss and good details in the highs make this headphone a steal for the money.
I didn't think that beyerdynamic made good in ears after a quite mediocre one I tried some time ago. However, with this one they have hit the sweet spot of sound quality for money. I tested them with an AK100 Mk2 and a Fiio X5 (also stacked with C5D).
For $100 I am not sure if it's the best deal you can get, for a substantial discount though you hardly find anything comparable with 2years warranty and service centers all around the world.