CRM Comparisons

Hello,

Looking to migrate to a new CRM system for my Customer Service department and wanted to see if I could get some real world feedback from users who currently use one of the following systems:

Salesforce Microsoft Dynamics Oracle CRM

I would be interested to know the good, bad, any and all feedback you might have. Even better if you used one of the listed systems and changed over to one of the other listed systems and you thoughts on the change.

Many thanks!