just wondering whether tiger or leopard would run better in an almost 6-yo powerbook? Would 10.5 be resource-draining for the powerbook with these specs? Also, should it run older versions of iLife, Microsoft Office, etc.. to keep it running snappier? Is it worth it to spend some money to upgrade the RAM? If so, what kind of RAM and what is the maximum that it can take? Obviously the machine is out of warranty at this point... Many thanks in advance!