[Nexus 5 Q&A, Help & Troubleshooting] mmmmBACON:
I have yet to find a Qi charger pad that can output above 1A max to a device. That includes the official Nexus 5 wireless charger, GMYLE, Tylt Vu, Samsung etc. That's regardless of price ranges.

The official Nexus 5 charger for example takes 1.8A from the wall adapter to the charger, then the charger plate outputs the same 1A as everything else.

Factor in ~70% or so efficiency, and Qi chargers will generally max out charging the Nexus 5 at around 700 - 750mA.

I used CurrentWidget to compare the stock Nexus 5 wired charger and my generic ebay Qi charger using various connections.

This is what I got for max sustained charge:

I used the Stock USB cable for all of the variations.

Stock 1.2A LG wall adapter: 1053mA

2A USB wall adapter: 1053mA

Built in USB input on power bar: 1053mA

USB 3.0 port (desktop computer): 446mA (surprised it was so low for a USB 3.0 charge port)

USB 2.0 port (desktop computer): 334mA

Generic Qi charger (2A input/1A output)/Built in USB input on power bar: 751mA

Generic Qi charger/Stock LG adapter: 655mA (corrected, sorry typo)

Generic Qi charger/2A USB adapter: 751mA

Generic Qi charger/USB 3.0 port: 696mA (interesting compared to directly plugging into USB 3.0)

Generic Qi charger/USB 2.0 port: 502mA (low, but again higher than direct cable)

So looking at all of these, as well as looking at the stock LG charger (as well as a higher output 2A I had around), I couldn't get any higher than 1053mA charge rate regardless. I'm sure that's due to some built in settings in the Nexus 5.

What was more surprising (unless I screwed something up) was the crap charge rate using direct USB cable connection into a USB 3.0 charging port. It was only a little bit of an improvement over USB 2.0. This was somewhat negated using the Qi charger into the same desktop USB ports (which surprised me further) but still wasn't as efficient as directly into a power outlet.

So, if there ever is a Qi charger that outputs at 2A, given (from my anecdotal test anyway) a direct cable using a 2A adapter gave the same 1053mA max charge rate, I think the most you can expect is getting a little closer to the stock plug. I don't think wireless charging will ever be faster (or even equivalent) than wired given the efficiency loss, even if it was higher output. (My guess anyway) I think the 1A Qi chargers out right now are giving roughly what you can expect for Nexus 5 max wireless charging. It might even be limited like the wired charging seems to be.

I think the more important thing is, not to use the USB ports on a computer, even if it's a USB 3.0 charge port. Using the Qi charger to the computer it was still less than max the Qi was capable of. I've ordered 3 more 2A adapters to use with the Qi charger I have, plus the 3 additional Qi chargers I've ordered just to make sure I'm getting the most out of it.

So if you can find a cheap Qi charger (like the ones I posted earlier) you might as well go for it. As long as you check that the output is 1A, they essentially (charging wise) perform the same as the chargers that cost $20 - $50+ more.

If anyone can do any other tests with their Qi chargers to confirm or negate my findings, that would be great.