CleanMyMac X

Pros: Good UI design and some useful tools. Also useful for quickly reducing RAM usage when that was close to 100% used.

Cons: Support was terrible and so I found that I had been paying for 3 subscriptions despite having just 1 computer. When I contacted support I was given the run-around. What made this even more annoying was that despite having a paid subscription I was unable to use the software on my computer. I was never refunded any money and wonder why they felt charging for "active" plans I could not use was acceptable.

Overall: I enjoyed using this but at the3 x cost it is cheaper to go use Avast. However when the support team takes so long to answer and then gets it all wrong, I have to look at the cost vs, my time. Despite the tool doing much of what I needed I cannot recommend this to any of my friends as when things go wrong the support is not there.

Pros: CleanMyMac has an attractive user interface but it overloaded my Mac the animations were janky and then tried to scare me into paying.

Cons: CleanMyMac slowed down my Mac. Demanded a 40 USD yearly payment to continue cleaning after removing just a few items. Tried to scare me with big red fonts saying my Mac was at risk. At risk from what exactly that is was not made clear.

Overall: Got the free download but it demanded a 40 dollar payment to continue cleaning after removing just a few items. I only downloaded it because I saw lots of posts about it on reddit and youtube. In hindsight these must all be paid promotions.

TLDR; CleanMyMac is malware just like MacKeeper!

Pros: -Good selection of optimization tools
-Fast performance, easy on CPU
-Customizable settings and actions
-Updated regularly for current OS X version
-Affordable

Cons: - "Junk Cleaner" can reset important preferences
-Best results requires intermediate to advanced OS X knowledge
- App Updater can be unreliable

Overall: I have been using Clean My Mac X (CMMX) for over 10 years to fine tune and optimize the performance of my Apple Mac Laptops and Desktop Computers. It has become a staple of my computer maintenance routine.
CMMX is built around a great looking and easy to navigate GUI (Graphic User Interface). Each section is clearly arranged by function. This allows the user to choose which tasks to run and how specific each task is. If you have at least an intermediate understanding of Mac OS X software, this level of control is very useful. I often find I only need to run certain tasks at different times and I've learned how to generally diagnose poor performance on my Mac and therefore zero in on the few operations to run within CMMX.

If you are ac beginner, CMMX is set up mostly well for you too. There is a single button to click that will scan your entire Mac's software and report to you suggestions for what tasks to run. Most of the time the user can simply click " OK " and CMMX will do the rest, sounding a clear chime when complete.
My only caveat with this one-button function is if you have highly customized OS X and/or are dependent on browser cookies and certain complex preferences. Since CMMX wipes nearly all temporary (and always recreated) files and cache, you could run into some annoyances having to log in to all your favorite websites again or set up some of the basic OS X preferences again.

Thankfully CMMX allows the user to review all changes before executed. This is where some basic Mac and general computer knowledge comes to play. You can sort through a long list of user and system files that all are safe to delete but you may want to keep many such as browser cookies for convenience. Feel free to experiment here - Nothing you do will break your Mac. You may just notice some settings are back to the default.

Additionally, there is a malware scanner, network health checker, old app and files scanner, RAM optimization feature, secure trash cleaner and many more features to use. There's also a virtual assistant that offers suggestions as you use your Mac on a day to day basis. It runs pretty seamlessly in the background and makes helpful suggestions.

While it has good performance and is updated regularly, the Clean My Mac X menu item can be a little imposing. This is an icon that resides in the main Finder toolbar of OS X. When clicked, it offers tons of stats and real-time checks of your system. Many of them are not useful but for only advanced users. It takes up a good bit of memory too. But with most things in CMMX you can disable this menu bar item in the settings.

I recommend for users of all levels to read the manual thoroughly. It's short and informative and can really help to give a better understanding of how OS X works and ways you can keep it's performance optimized and clean-- both by using CMMX and by following a few basics on your own. (Most importantly, ALWAYS be sure to backup your files before running any tools or cleaner apps.)

Clean My Mac X is a great companion tool for Apple's OS X software. I also appreciate the affordable yearly subscription, though you can try it for free and use the basic functions. I started using Mac devices over a decade ago and Clean My Mac X helped immensely to keep my machines in tip top shape and also helped my overall grasp of OS X and how my Mac runs.
While a few areas can be improved upon in my opinion, the developers seem to work on adding features often and releasing auto updates regularly. I Highly recommend you give CMMX a look.