
Hi interactive,
Thanks for the question.
The principal difference between the ChainedSSL and the Professional Level certificates is brand awareness. GeoTrust brands are highly credible and internationally recognised.
If customers are running high volume sites, we would recommend that they purchase a Professional Level cert. to ensure that they maximise end user confidence.
Other differences include;
- GeoTrust certs have more browser ubiquity and are compatible with 99percent of all browser types
- They are single root certs, meaning that for installation, there is only one component to install
- Multi year certs available
- Active site seals available
The FreeSSL web site has a number of places that you may find useful that details more on Professional Level certs and ChainedSSL, please take a look at the following;
http://www.freessl.com/faq.html
http://www.freessl.com/comparison.html please also try the product selection wizard
http://www.freessl.com/resources/guides/whitepaper/secure_business/page1.html gives an indepth analysis of all the factors that should be considered when purchasing SSL
Let me know if I can help further.