Although it might seem obvious, I rarely see hotfixes being implemented in real life. In the past, implementing a hotfix usually required a manual fix on all clients, and on the server. This is a time-consuming process because you usually have to visit the customer site to do the installation. There are also a lot of hotfixes to implement, depending on the version of Dynamics NAV that you use.
Nowadays, with PowerShell and Click Once technology it's easier to automate this process. Microsoft releases rollup updates about once a month. So, if you experience performance issues, have a look at the Microsoft knowledge base to see if there's an update that might solve the problem.
Note
A good alternative to the Microsoft knowledge base is Waldo's blog, which you can find at http://www.waldo.be. He gives an overview of all released platform updates on a regular basis, and I find it easier to see the wood for the trees on his blog.