One major difference is that you can't execute custom scripts (like using PHP, ASP, RoR, etc.). This is for a variety of reasons, security being number one.
As for the safety and integrity of the server infrastructure, we are housed in a SAS 70 Type II and CICA 5970 certified facility with regulated climate control in accordance with ASHRAE Guidelines
, a 100% Power and Network Uptime guarantee, military-grade security, and it's staffed with engineers certified by Cisco, RedHat, MySQL, Microsoft, and others 24/7. It's the same facility used by local governments, and a good number of Fortune 100 companies.
Our cluster was designed with the help of high-level engineers from RedHat, MySQL, and Cisco, and is monitored constantly for errors and outages. A testament to this is that when our own website struggled with the load of people hunting for eggs
, S-Drive hosted sites were up and running without a glitch.
All that said, we think your site will be just fine.