Just as a reference, mine started at 45-50% free
memory as well. With a ton of screw'n around
on macros and device panels, I got the free memory
down to 15%. So just for curiosity sake, I
intentionally added/deleted devices until all
free memory was exhausted. After the memory
purge was completed, I ended up with 34% free
memory. My current approximate configuration
is 8 devices (about 3-4 pgs each) and 25 macros
(about 5-10 commands each), all at a cost
of 10-12% memory available, so I wouldn't worry.