I like the set price, regardless of users, this makes it easy for me to create an app without fear of the cost each month. Originally i had planned to use knack to create apps as proof of concept, before commiting to further development. I was pleasantly surprised that we actually don't need to develop some of the apps, as knack as many features that cover the needs i have.

Simple and instuitive to use. Definitely take some effort to learn, but the learning curve is not too steep.

Knack is simple enough for about anyone to build very useful database apps. But at the same time, it is extremely robust allowing very high end functionality for users with a little more experience.