Gentoo Linux has always had much to offer any user that that wants deep control over their Linux computer. But nothing is free in life, and Gentoo exacts a price from each Linux user by requiring a certain level of knowledge in order to get the most out of it.
LinuxInsider looks at the pros and cons of using Gentoo Linux, and finds that Gentoo may be too difficult for some users.
According to LinuxInsider:
The main advantage to using Gentoo Linux is its performance and customization. These two factors far exceed what the user settings in the KDE desktop provide.
Another benefit is the source compiler maximizes all possible optimizations and makes the software run as fast as possible. However, on less-powerful computers, this process can take what seems like forever to complete.
Another major disadvantage of Gentoo Linux is the difficulty factor. You can not expect to install this distro easily and have it work out-of-the-box. Mastering Gentoo requires an investment in time to navigate its steep learning curve.
I've always thought of Gentoo as an acquired taste. Those who choose to use it generally seem to know what they are doing, and also what is expected of them from Gentoo. It certainly is not a distribution for folks who are new to Linux, or who just want their distribution to "just work" with no input from them. You will get out of Gentoo what you put into it.
I'm very glad that Gentoo is around though since it offers a very different choice than Ubuntu or Linux Mint or any of the other distributions that are geared toward users who just want them to work "out of the box." Not all users are like that, and it's important that those who require a deeper level of control of their distribution can get it. And Gentoo is indeed a great option in that sense.
So I think when we consider Gentoo versus other distributions, it's important to note that we are basically talking about apples and oranges. Certain distributions are meant to be installed and configured with little input from the user, and others require knowledge and experience to use properly. What's matters is that Linux continue to serve both casual and more sophisticated users, and Gentoo is an important part of that effort.