We explored a number of CRM solutions and initially selected Insightly after trying to get Tiger CRM working. Insightly functionality was too limiting and consequently was not being used. Our second round of trials lead us to Nutshell, which we have been using for about two years.
We found Nutshell to be reasonably robust and easy to use. We have been using it for about two years now. We have about 30,000 contacts and 11,000 companies.
We are now running into some functional issues which we have to address with addons, including Mailjet for email campaigns and Zapier for data transfer. The lack of a quoting interface, manual address entry into Quickbooks, lack of phone integration, and incomplete email integration. With the exception of QB integration, the other functions can be addressed with more addons. By the time we get done adding on the functional holes, the price becomes quite high.
The reliance on addons also means that the system becomes unwieldy; a different system, management interface, and subscription for each function.
At this time, I don't think there is a good solution for QB integration at all. This may not be significant since QB for Manufacturing is below our needs anyway. Our next step may be to use PostBooks, Xtuple, or some other MRP system that includes CRM. But, those also carry their own management burdens and costs.
Nutshell does have a reasonable email interface to send correspondence through our IMAP server, but the markup tags are cumbersome, are error prone, has no CC or BCC field, and the reply emails don't populate under the Nutshell customer(s). Consequently, only half of the conversation is visible. Of all of the above, this is the most significant limitation at this point.