I could give you buzz kill answers or the other side.
I would try and do a pro/con. Here are five in no special order to start it rolling.
Con-
it is more parts to break
more weight
saps energy from pedalling
expense
more maintenance
Pro-
wow-factor
comfort
they say that it increases your endurance
more parts to replace (if you are a techno weenie)
downhilling is a blast!
If you are unsure, I would test ride a few and see if they can preload the shock enough to accomodate your weight. That is the real issue for bigger guys.