- Robust integration with Salesforce. Can see and edit all custom object records, as long as you can access it through an Account, Opp, Contact, or Lead through a Related List
- Also includes a scheduling tool that takes into account conflicts on your calendar
- Ability to add emails by default, or manually add a specific thread, including ability to select attachments
- Great customer service -- usually responds within a day, and almost always resolves issue on first contact
- Good looking UI in Gmail
- Ability to track email opens, and exclude internal org opens
- Schedule emails to be sent at a later time & automate follow-up task scheduling
- Intelligently shows relevant fields (including fields required by validation rules) when creating a Lead, Contact, or Account, not all of the fields
If you're looking for an email blast tool, Cirrus does it, but Yesware specializes in it. Only in the Closer edition of Cirrus does the Campaign feature exist. If you're planning to do more marketing heavy emails, use a marketing automation tool, not Cirrus.
If you're looking for an easy window into Salesforce in gmail, Cirrus' inbox panel and visibility to Salesforce custom object/related list features are more robust than tools like Inbox IQ (ATM) or Groove. Can't say about the other tools.
Prevents me from needing to switch screens to access Salesforce when writing an email
Allows me to instantly see if Contacts or Leads are in Salesforce at a glance without opening an email