When the designers made Gentoo, they decided to give the user full control. This is great, but it means that you have to do a lot of heavy lifting. The settings and tweaks are not the most obvious until you have read up on processors and many other parts of the system.
If you pick one of the derivatives, you can cut the learning curve and still have the advantage of tweaking your system for your hardware. When people create derivatives, they have a special need. When this need matches yours, you have a derivative distribution where most work has already been done. You can, of course, still tweak, and hopefully, contribute back to the community.
Calculate Linux comes in many flavors; this includes Desktop, server and cloud. The Desktop comes in many editions to support Cinnamon, KDE, LXQt, MATE and Xfce. You can also get the Scratch that has the X server. You can also go the other way and get the Xfce Edition Scientific. As you can see, there is a great choice of desktops and since it is Gentoo compatible you can also set your choice of Desktop afterwards. Using the Gentoo Portage system is complex and needs a lot of practice to master. You may end up with a very fast machine, but setting up will not be trivial. Calculate has a graphical setup feature that shows all options, and you can choose any edition you want from that installer. You need to know what partitions you want if you want to use existing ones and so on. Once you have made your choices, you need to wait for installing and compiling your software. The installer reminds me of the old days when nothing was assumed. You had to know what you were doing. With that said, if you know these things, the install is all done for you and updates are handled automatically. Calculate also comes as a server, a cloud instance using lxc, and you can create a server to handle all the users on your network. The server is an LDP server specially set up for this distribution; you can also use it for other operating systems. The glory of open protocols!
As you may guess from the name, the Pentoo Linux is a specialised distribution for penetration testing. You are supposed to put it on a USB stick. The design goes so far so that you can save your changes to the stick. This is not advanced, but few people use a USB stick that way. When installed, it comes with the XFCE4 window manager to stay lean. The other tools of note are opencl cracking library and a kernel for hacking WiFi connections.
This distribution looks like the others when it comes to packages that are included. You get a full set of office tools and the browsers you may need. You have several packages for maintaining the system and software. The ISO comes with a nice installer. This needs a lot of memory to use; the install option from Grub is a much faster alternative. You do have fewer options than from the live environment. You can let the installer partition the disk for you or roll your own. Tested packages you can pick up include Kodi for playing videos, many server choices, and a home desktop system. As with many Gentoo distributions, you also have the option to run a cloud edition. They are available as Docker, LXD/LXC and Vagrant image.
This is the one you must consider. Why? Because the founder is the lead developer for Gentoo! This does not mean that it meets your needs, but it means it is fully compatible with Gentoo. In fact, installing it, you should use the Gentoo install ISO and download the stage3 file that suits your system and needs. In this case, you are also stuck with the same install as Gentoo. The only difference is that you can get many different stage3 files. You can choose a desktop environment in this step.
Again, as with the other distributions, you also have cloud versions. LXD is the maintainers favourite; you also have Docker images. The way to start them and use them are well documented on their website. This distribution has the advantage of having many well-tested versions that you can download as stage3 files. The other distributions also have great installers so that they will save you more hassle. Not that you would choose Gentoo is if you want to avoid the hassle.
Choosing a derivative Gentoo distribution will help you to get started with Gentoo and the package management system quicker. This is great if you have just a few things you want to tweak. It is also useful when you the option to perfect your settings in the future. In general, you should shop around for a distribution that matches your needs and consider a community surrounding the distribution you will have much in common with. For active computing, you need an active community.