From the design perspective, I don't agree with the supplier recommended data
sheets regarding footprint criteria.  As you point out the separation between
large land area and individual I/O lands is very small (ie .002-.005) I
beefed mine up to something like .010.  I don't like the solder stencil
pattern either; they would have the paste offset onto the mask by .010-.025.
I didn't do that.  The LLP doesn't require special surface finish or exclude
any as some would indicate.  First pass success is needed due to quite
challenging to rework.  We built quite a few parts to shorts adding the LLP
by hand, never do that it was ugly.

Those are the areas of "gotcha" concerns; every component has their own
gotcha's.  I like the LLP package, used as intended it is very nice.
Especially if it is replacing odd form parts.

Brad