Pros
The Force.com platform is a compelling business story. Young and fun group of employees.
Cons
Subscription timeframe too short - With subscription renewals of 1 year (some are longer), some companies are not yet live - as such, they are not interested in renewing. Tough model for a SaaS business. Services - the implementation partners and FFDC resources are overwhelmed and once a project is completed, they do not have time to go back for post go live fixes or additional assistance. Plus, since everything is custom (see next point) and undocumented, it was difficult for anyone else to step in. Custom approach - When I was there all the FFDC products were uniquely built without any standard configurations, no documentation was provided and since everything is built from scratch tech support had a difficult job of troubleshooting issues. Customer resources - ideally a customer has a SFDC administrator to manage their system and make updates. FFDC's customers tend to be on the smaller side and are unable to maintain enough work/afford a full time SFDC admin. Ends up causing a lot of pain and confusion for the customer. Version control - SFDC may upgrade at any time, thus breaking the custom coding in FFDC. Saw quite a few customer situations that ended in FFDC & SFDC pointing fingers at each other as to who was a fault. There were also different versions of FFDC customers were on, causing further confusion.