Decided to get the 11".
While the 12.9" is definitely smaller and has shows more, usage for me is important. E.g using in horizontal and vertical mode.
I can see myself using the 11" alot more in both. This 12.9" was a little fatiguing for me in horizontal mode.
The 11" felt considerably lighter to me when using.
That said, you can't go wrong with either.. Gorgeous devices. Just get what suits your needs. YMMV