Updated: September 28, 2019
You know I'm no Arch fan. But I am also impressed by the efforts to transform the ultra-nerdy Arch into a friendly system accessible to the masses. This is primarily done by Manjaro, which is blazing an honest path of creativity down the Linux highway. I've recently tested version 18.0.4 Illyria Plasma, and found it to be quite solid. There were lots of problems, but then, there were also some super-cool features.
To help you get along, I've compiled this article - it's mostly the summary of tweaks and changes I introduced to the installed Manjaro system, in order to get a smooth, seamless experience replete with good software, good looks and proprietary drivers. Now, there's also the Xfce review, and we might do some tweaks for that edition, too. But now, we only focus on the Plasma spin. To wit, let us commence.
1. Free versus nonfree
This is almost too trivial - but easy to not notice. When booting into the live session, the Manjaro menu allows you to switch between using free drivers for your hardware, like Nouveau, or proprietary drivers, like Nvidia. This is not limited to just graphics cards, but it illustrates the point well. You might not notice this, and you could end up using the distro in a mode you did not intend. If you do choose nonfree, you will have the proprietary drivers out of the box, and you won't need to do any other setups.
However, even if you do make a choice - you can always change it afterwards. In the Settings tool, there's an entire section of Manjaro-specific configurations - these used to be previously offered as a separate control panel, but they are now nicely integrated into Plasma. Here, under Hardware Configuration, you can select what drivers you want to use - open-source (free) or proprietary. There's also a wizard to setup graphics drivers automatically.
2. Package management tweaks
This is the most important element. By default, Manjaro Plasma uses Octopi as its UI frontend, and pacman as the command-line utility. You have access to several repositories with a decent set of programs, but Manjaro no longer supports AUR (officially), which means many third-party packages aren't instantly available.
You can work around this by using a second package manager - pamac. You have the option to install the command-line tool (pamac-cli), the UI (gtk version is default, qt is experimental), and also the tray indicator that works well in Plasma desktops.
Once Pamac is installed, launch the program, and then change its settings to enable AUR. Once you have this functionality, you can search for third-party software and install it. You can continue using pacman for normal system updates without conflicts (within reason).
3. Additional software
The next step is to install some nice programs. In the Plasma edition, I needed GIMP and LibreOffice, but then you can install tons of other cool programs (like say Kdenlive, Clementine or Chromium). I also installed Google Chrome and Skype via Pamac/AUR. You can use the graphical package manager or the command line.
pacman -Sy gimp libreoffice-fresh
4. Theming tweaks
In the Plasma test, I noticed that Microsoft Office Online icons were not available in my installed system - this could entirely be the result of re-using the home directory. However, if you encounter this problem, you may want to consider testing different icons themes. For me, neither Breeze nor Breath offered necessary icons, but Papirus did.
5. Icons-only task manager tweaks
I also noticed some inconsistent behavior with several applications. Namely: the icon would change depending on whether the application was running or not; pinned applications would show up with a second, unpinned icon at the end of the task manager; pinned applications would not always start. The easy solution to this issue was to pin applications through the system menu rather than using the right-click menu for running programs. This sounds like a glitch, but if you encounter it, you have this tweak.
6. Samba sharing
By default, Manjaro Illyria does not ship with the necessary package that allows Samba sharing. To that end, you will need to install the following - and possibly also make a manual client protocol tweak to be able to connect to Windows boxen.
sudo pacman -Sy manjaro-settings-samba
7. Samba printer browse & configuration
This may only be specific to the Plasma edition - but the Browse button in the Samba share configuration section in the Printer wizard is grayed out. I did try several tricks, similar to my attempt to enable printing in CentOS 7, but none of these really helped.
However, you can always resort to the same old trick I've tried in various KDE distros where the problem would manifest - use the system-config-printer, the old Gnome 2 era utility that always works. If not installed already, then grab it:
sudo pacman -Sy system-config-printer
Run from the command line, wait for the wizard to launch, and configure your printers!
Conclusion
Thus endeth the article. Hopefully, this was useful. Overall, Manjaro has a lot of cool features, but it also suffers from various sub-optimal default settings. Luckily, changing most of them is relatively easy, and in the worst case, you need to install a few packages. The biggest challenge is installing third-party software, for which you need AUR (unless you want to do things manually). But it's all doable.
With some luck, these issues will be ironed out in future releases of Manjaro. If not provided as defaults, then at least, there will be an easy path for users to grab the desired software and install it in a friendly, simple, straightforward fashion. Well, I guess that would be all. Manjaro away.
Cheers.