They do not nickle-and-dime you to death! One price includes everything. Their tiers are about number of users rather than adding/subtracting features. A more sensible model than some of the others.
I like how detail views are available from most places -- call logs, projects, tasks, and notes can be associated with a contact or company or opportunity.
The integration with email is excellent, right down to making it easy to connect your email boxes. One challenge I had that Apptivo solved for me was how to keep emails related to a particular project or opportunity all together in one place. Apptivo does a good job of this by assigning codes (or project numbers), and allowing you to select whether or not the email you are writing is related.
If you are writing emails using some other application (your desktop client or cloud-based app), you can use the same code in the subject line and Apptivo will pull that email into the app, and associate it with the relevant modules (project, client, case, etc.)
Apptivo is reliable, doesn't seem to ever lose information, etc. but it is often as slow as molasses in an ice storm. Waiting is a no-no; constant waiting is a annoyance that has made me close the app more than once and come back another time.
Apptivo communicates improvements and changes on a regular basis, however, it takes Apptivo a long, loooooong time to integrate changes that have been requested by clients, and improvements overall.
The incremental changes they report on are good but they are really things that should have been implemented 4-5 years ago. An example of this is Stripe (payment gateway) integration. I requested it over and over about 3 years ago but it was just implemented last year.
They could do better with customization (esp. dashboards), reporting, data import, data export and speed.
Low scores on API/integrations -- they have an API but not many other services have developed integrations for it. Neither have they developed many integrations (except for Google products). Even their WordPress module is outdated, clunky. Also, connection to phone services (to take better advantage of the ability to log calls).
The interface still has areas that are clunky and unattractive (although, in defense of Apptivo, I must say the interface has improved in aesthetics, colors and icons in the 4 years I've been using it).
Response from Apptivo
Thank you very much for your kind words! We are working tirelessly to create the best experience for our users, and it's great to see that reflected in your review. I am sorry to hear about the problems you faced and we are looking into that now. We exist because of great customers like yourself! Please feel free to reach out to us (firstname.lastname@example.org) with any thoughts/criticisms/feedback, we would love to hear from you.