Lots of reasons to upgrade:
including
better core management
speed improvements
X2 bits and pieces.
current upgrade price is ~~42.50
stupid start menu/wall
Lots not:
no time to learn/configure
don't wanna
only computer and in middle of big job,...
favorite programs will not work ith 8
stupid start menu/wall
Best approach:
use external disk to create disk image
partition the OS disk
install w8 to new partition: now you have a dual boot computer
add programs, drivers,.... as you have time
continue testing until satisfied all is well
use 8 all the time