Yes, used/tested a Android Samsung Galaxy 2 Tablet and Ipad 3 (at the same time !) with a lot of Pleasure :-)
Found nothing real negative.
I tested and described it here:
www.tacklefever.de/index.php?topic=2982.msg24021#msg24021
On the tablet you will get a Screen Size that comes near the HDS Gen 2 9".
The Resoloution of the 7" and the 9" Units are the same, 800x480 Pixel,
so it seems like with an Ipad or any other tablet you will get mostly the same Screen Size but with a less Price.
Measured on the HDS 7" diagonal approx. 17,5 cm.
On the Tablet diagonal approx. 22,1 cm.
This means 4,3 cm or 1,7" more.
Tablet In comparison to the HDS 9 maybe tablet is about 0,8 cm less !
In my Thread there was also a Video to demonstrate the Speed while using the HDS remote from the Pad.
I think this is realy great... having a tablet in Front of the Boat, and the unit on the console,
maybe a second tablet in the back of the boat so both Anglers can see whats happen.
Here is the Link to the Posting with the Test:
www.tacklefever.de/index.php?topic=2982.msg35076#msg35076