Re: Amen!
I also use Qi all the time (and have even retro-fitted Qi charging to all my devices, including phones and tablets that don't come with it--not with a case, but actually adding the electronics inside the phone/tablet). I can hardly remember the last time I had to plug a micro USB cable in, as I simply have a Qi charger sitting enywhere I am likely to want to put my phone or tablet.
To answer your question, Qi is a bit fraught in some ways and the different priced chargers on the market definitely reflect varying quality--but sometimes not in the way you'd expect. There is lot of stuff in the Qi spec about e.g. communicating the actual power needs of the device to the power supply in real-time, so it can continually adjust its output accordingly. But if the charger is a cheap rubbish one, it may not support this protocol correctly, and blast out maximum power all the time, causing overheating. But again, I have a stack of cheap $2 no-name Qi pads and they seem to be as good as or better than some of the very expensive ones with fancy marketing. YMMV.
I don't doubt that Apple has this absolutely nailed with their end-end implementation. And Samsung and Google Nexus has always had great wireless charging support--they seem to have more flexibility about positioning, and smartly PWM the charging, or stop charging with a message if too far off-centre. Also, Samsung phones show an alignment marker on-screen the moment you move it near the charger, making it trivially easy to position exactly right.
The elephant in the room with Qi is that you have to line up the phone to within about 10 mm to achieve optimal inductive coupling without too much loss to heat (and corresponding early death of your phone battery). Also, the phone has to sit almost directly on the charger, so that even a slightly-thick case can make charging unreliable in some cases. In theory max Z-height is 6 mm, but this is not always achieved, depending also on the materials in the gap--air is different from a case with possible metallic parts. Supposedly the resonant charging features present from Qi 1.2 address this (giving 30mm+ Z height/offset), but I have yet to find a Qi 1.2 compliant charger or phone with those specs.
Despite its limitations, you soon get used to wireless charging, and I would never be without it.
I've not observed any adverse effects on magstripes (another feature of Qi that may be supported to better or worse degree in each charger is detection and avoidance of foreign objects), but the thickness of your card and case may be enough to make the Z-height out of spec. Depending a lot on the charger and phone in question.
If you understand the limitations and it still fits your use-case, I highly recommend it. You could always dip your toe in the water by buying a cheap charger and see how it goes.
Biting the hand that feeds IT
