The decisive factor for my decision to Iconia A1-810 were the functions (see below) as well as the positive reviews for the processing as well as the performance. This I can confirm full, but spare me a renewed enumerate.
Since I have tried in vain, however, in various forums, to find information on the suitability of different devices for camera control, I want to address this point:
The A1-810 detects a USB OTG adapter cable (USB micro connector -> USB A socket) and the supplied Nikon camera for USB connection cable (USB-A plug -> USB-mini plug) without any problems, the Nikon D700.
The OTG adapter must be purchased separately, but is available for a few euros.
A rooting or other pull-ups as they were apparently required in previous devices with older versions of Android, is not necessary here.
To control the camera I've tried the apps "Helicon Remote" and "DSLR-Dashboard". Both contributed to the camera without problems and are currently available free of charge. They are similar in terms of functionality, run smoothly on the A1 and with me so far no crashes. Which program you depends on your personal preferences and requirements uses.
Only the use of both programs in succession led first to the fact that the launched a second program could not connect to the D700. After I had found, however, that the first in the background was still active, this problem lies fix by completing the first complete software.
In short, the positive properties of the described application:
+ Easy control of the camera (Live view in full screen mode, bracketing, etc.)
+ Optimum size / format for the photo backpack (10 "would have been too large)
+ Additional memory via Micro SD for the parallel deposition of the images (for example, offers not the Nexus 7)
+ HDMI output to the first common "images gleanings" on a photo tour
Finally, a note about the here described problems with the online connection via a mobile hotspot: with an iPhone 4S, I had not the problem. The hotspot lies to connect easily and use.