I recently acquired a new power adapter 85W for my macbook pro retina late 2013. I made sure the specifications matched the official Apple adapter and in fact I have not noticed any performance issues.
The problem is the green light on the magnet connector is sometimes blinking. I am wondering if that could could cause any damage to my battery or have some other issues. Otherwise it charges properly and battery duration is normal.
This is the product by the way: http://www.amazon.co.uk/Magnetic-Charger-MacBook-Retina-Display/dp/B00BJ97CWU