"...make sure you have your I/O assignment figured out BEFORE you commit the pinout to the PCB layout."

So the Triscend really scores on that one - all the PIOs really are fully configurable; once you've got the memory, power, and just a couple of other "fixed" pins tracked you can reassign the pinout to your heart's content!

"3) The Cygnal parts are all 3.3V parts in surface mount packages that are not economically socketable."

Same applies to Triscend.

"...Cygnal does have very inexpensive evaluation boards"

Don't know about Triscend.