When it comes to USB, test your equipment, even if you haven't upgraded to Type C yet.
I've personally discovered two counterfeit or substandard (depending upon your personal definitions of the terms) USB charging cables.
What I use to test is a Samsung Galaxy Tab 3 10-inch tablet. This tablet wants approximately 0.7-0.8 amps at 5 volts, but it will charge in a degraded mode if the charging cable isn't up to snuff, or if it's plugged into a desktop or laptop (which normally only supply 0.5 amps).
Every cable should begin by charging in the degraded mode when plugged into my laptop and then upgrade to normal charging mode when plugged into any of my half dozen or so 2 amp USB chargers. Among over a dozen cables, I detected two that were not up to snuff, and you'd be surprised at my results. One cable from the dollar store was garbage, but another, colored cable from the dollar store that had fancy LEDs was fine. Three 10 feet cables were fine. The other reject was an average-looking cable with an average feel. It did not appear to be substandard or counterfeit.
If you want to get fancy you can get a device from banggood.com that measures current and voltage across the USB port. They cost about $3 shipped. That is how I determined that my tablet will draw approximately 0.7-0.8 amps. From that experience I'd be surprised if many devices actually draw a full 2 amps. It's nice to have a 2 amp supply, though, because it gives you a safety factor if your cables are somewhat substandard. Maybe the newest 2016 phones will draw close to 2 amps. Get the meter and find out!
Based upon my experience, the best USB chargers are from Samsung and anything else that has a counterfeit-resistant UL sticker. And also based upon my experience, if you notice that a charging cable is getting warm, you should probably replace it because it's dissipating electricity as heat rather than conducting it.