I contacted ZENS, and they told me that, it do work with nexus 5 & 7 at the same time, I don't know the tech specs, so I'm waiting for reply, from them.
Also, my problem is the size if current single pads, and I don't need a travel solution, just good charger for home use only, they just too small, not in terms of, that they not work, but it not looks good with tablet, as they made for smartphones, the ZENS dual, at least have size, also, it not like those cheap Chinese one, it has multiple coils, and that important to know when talking about cost, also, I don't care to spent 100$ on it, because more and more devices out, with "qi", so it will be used with other devices, It's like laser printers, they cost more than inkjet, but they print and print more with one toner, so if you buy something, that will be used for long time, just buy the best you can,or at least with a good value for long time. As for the charger, I think it has 2-3A input, but has some circuit, that allow only 1A for each device...but not sure about it