The two pieces are quite similar although the magazines rate PAM 277 as a more 'collectable' item by virtue of it being a LE (250). The waiting list is pretty long and some of my friends are told it will be months before they can get their ordered piece.
You probably know this already - the '4-star' PAMs are 1, 5, 6, 7, 8, 21, 46, 65, 67, 80, 147, 194, 203, 228, 262, 317
There are of course more '3-star' PAMs, e.g. 4, 9, 23, 26, 28, 29, 36, 40, 64, 81, 82, 92, 108, 117, 127, 156, 162, 172, 192, 193, 202, 217, 222, 246, 249, 252, 253, 274, 275, 276, 277, 286
This is a rather subjective list, nor is it exhaustive...
Sam