I find them too long. Long names can distract from the intent of the actual code. They're supposed to merely combine domain-level logic, but being long they make the impression they're more than that.
if i see PAPPLY (or any other abbreviated name for that matter), my brain first maps it to PARTIAL-APPLY and then to the meaning itself.
IMHO, abbreviation is bad because it can be done in a million ways and it only introduces an extra level of indirection which is an (admittedly small) obstacle against understanding.
of course the picture is different for names that are used in every second line.
it might be only me, though. and i don't have strong feelings because names are inherently subjective and our tools should handle the personal preferences. CL + slime does not provide much in this regard, but packages and symbol aliases work.