I came across this review, I have not used Manjaro for a while I think I will be giving it a go over the next week or so.
Been running Manjaro 64-bit Xfce on my daily driver for ~18 months and it's been a solid performer (Core i7-3770, 16 GB RAM, GeForce GT 630 w/proprietary driver). If you're thinking about trying it, here's a few tips which can smooth out your experience:
If you're going to go with the Xfce version, check the Manjaro wiki pages about screen tearing. Xfce's desktop compositor doesn't handle VSync very well, so one of the solutions listed will give you a better experience than toggling VSync in Settings -> Window Manager Tweaks -> Compositor. (Can't really comment on the KDE version so you're on your own if you go that route.)
Keyboard shortcuts in Settings -> Window Manager -> Keyboard may need to be adjusted to suit your needs. Personally, I blanked out the shortcuts for workspaces 5 thru 12 (rarely use more than 4 anyway), as CTRL+F5 was in use and was getting in the way of refreshing cached browser pages.
Keyboard shortcuts in Settings -> Keyboard -> Application Shortcuts may need to be tweaked as well. At the very least, you could stand to add
xfce4-screenshooter -fwith PrntScrn and
xfce4-screenshooter -wwith ALT+PrntScrn, as they're not set by default (I don't know why).
Make sure you sign up on the Manjaro forums. Whenever they release updates, a new forum post is created with the details which may point out any potential trouble spots one might have before installing. Any feedback users have is valuable to the team, so if you have any problems you can't resolve, post the specifics in the relevant thread. Voting on your update experience is also valuable, so take the time to do so.