I have verified that it delivers the maximum my USB C charger delivers without any loss (in this case 61W), and don't doubt it will support the full advertised 87W.
Awesome, awesome, awesome! The USB-C nib and cable have the same quality one would expect from Apple. The cable has the same soft bend jacket on it as an OEM Apple Charger. The magnet assembly is strong and snappy so as not to accidentally separate even when shifting my MacBook around on the desk. I tested the breakaway function of the MagSafe-type connection and it feels just like my wife's Apple Magsafe on her MacBook Air. Enough connection strength to stay in place under normal use but not so much that it can even move the laptop from where it sits before decoupling. For my 2016 15" MacBook Pro, this cable/connector shows no difference in charging speed vs. the Apple OEM USB-C cable. What a great product!
I definitely love the USB-C to USB-C charger. I use it for my laptop, and it keeps my child from running past me and ripping it out of my computer. My only issue (not worth a star deduction) is that it occasionally doesn't register even though it connected magnetically. I just re-adjust it, and it works great. I've only had it for a couple months, so I can't confirm long term reliability.
The product is good and convenient. Solid cable, strong magnet. But sometimes when I detach the cable, the pin stays on the magnet. I recommend it.
I use this on my new iPad. It has a good strong magnet but it releases easily too. Good cable with extra strain relief. Buy it.