I’ve used several CRMs — Sugar, Insightly, Pipedrive, Zoho, SalesforceIQ, and of course, Salesforce. None has been as easy, intuitively designed (API + GUI), or feature-rich as Propeller.
The primary challenge with most CRMs is that they require too much maintenance, and maintenance usually means "duplication of efforts." You have an internal tracker, and your CRM. You have internal call notes, and CRM contact notes. Because Propeller has a fully-featured Gmail extension, however, you don't have to debate where to keep your "source of truth" for a given deal or prospect.
I've actually gone weeks at a time without logging into the web app, because everything is available (including live search) from the email extension.
If you have more than 1 business unit, ie a sales team for Product A and a sales team for Product B, you'll need them both to play nice inside the platform. While you can build different views, it's not currently possible (I don't think) to silo the business logic of 1 sales team vs another.
Set up a call with the Propeller team to discuss your needs, ie whether you should use certain features like Leads vs Contacts, Campaigns vs Templates, and so on.
We get 100s of inbound leads per month and it didn't take much analysis to realize that if we methodically followed up with them, asked questions, scheduled internal reminders, and conformed our FAQ into email templates, we could close a lot more business.
We also wanted the ability to import leads as fully set up customers in our web app, without asking them to manually sign up and plug in data (pricing, plan, special requirements, etc) themselves. Our web app admin panel now imports notes directly from Propeller, so we have just 1 source of truth.