What does the company do well? Nutshell is a really great product for a company just getting started, up to about 10-15 sales reps and a handful of different products, pricing, or configurations. The UI and UX is super intuitive and I have found that most people can ramp up and be productive in a matter of minutes. I persuaded several companies to shift from SalesForce, SalesForceIQ, Hubspot CRM, and PipelineDeals to Nutshell and they were all very happy for switching.
Nutshell also offers stellar customer service. Whether you do live chat or email or phone, they are super responsive, patient, comprehensive, knowledgeable, and flexible. Their customer service alone makes it worth using them over anyone else.
What does the company not do well? Nothing significant to my knowledge. I have heard that for larger companies or for very complex sales operations (like with many many products, variable pricing, or similar issues), it can get outgrown. Its ability to customize fields and screens is pretty good, but not nearly as much as something like SalesForce. On the other hand, customizing SF usually requires an expert or a paid consultant. No such worries with Nutshell. It's easy to customize and for my needs with many companies, it has always been wide and deep enough.
What do you wish you had known about the company before using? I wish I had known some of the data-import and data-scrubbing limitations. It would NOT have deterred me from using Nutshell, but I might have imported my data differently. As it was, I had to take some extra steps after import. It wasn't a big deal.