From 5D I — Would I be happy with the 6D?

I am currently using the 5D (original )and am feeling the need for an upgrade because of want of higher resolution. I shoot mostly travel and landscape and enlarge up to 30" x 40".

I know that the 5D III is the "logical" upgrade but am also considering the 6D as it has been described as being an "ideal choice for portrait and travel".

I do like the idea of lighter/smaller in the 6D — The biggest factor, I think, is the differences in focus, but also how they compare in other aspects. Does anyone have both and can share recommendations?

TIA,

Geoff