Pro and Con

Download updates from Office Mac or use AutoUpdate under Help in the menu bar. More Info on updates

Pros
Verisign	Thawte	Instant SSL
Fee is relatively cheap.	Totally free.	Totally free
Can assume high level of security	Can assume high level of security	Can assume high level of security
One of, if not the biggest, public certificate authority in the world.	Also a large CA, but now owned by Verisign.
People will most likely not have to import the root certificate since it comes shipped with most systems (less hassle).	People will most likely not have to import the root certificate since it comes shipped with most systems (less hassle).	People will most likely not have to import the root certificate since it comes shipped with many systems (less hassle)

Cons
Verisign	Thawte	Instant SSL
Free Trial ends after 60 days	N/A	N/A
Can’t change/customize your Distinguished Name in the certificate or the extensions	Can’t change/customize your Distinguished Name in the certificate or the extensions.	Can’t change/customize your Distinguished Name in the certificate or the extensions.
Can’t submit your own request (CSR)	Can’t submit your own request (CSR).	Can’t submit your own request (CSR).

Pros