I am still on CMS 2.7 and won't head over to the new version until it has the firewall. Antivirus is good and nice, but without firewall it is only half the game.
BTW since marshmallow, the System optimizer of CMS 2.7 seems to work properly. If you let it run and before you klick "Optimize now", it Shows more and more apps in the cache. even more apps than installed. If you click to optimize the optimizer shows "XY apps with ABC bytes in cache cleaned" says "Optimizing finished" and then runs and runs and runs cleaning and cleaning (more than once the same app). When you hit the "back" button of the phone, thus coming back to the overview of the system optimizer, it shows sometimes even more apps in cache than before.
Therefore I use the "Memory and USB" option of the Android settings. This works fine.
I have an Nexus 5 and keep it nice and clean, even wipe the cache partition after every system update, and all the other apps work without trouble, so I don't think these problems are caused by my phone.
I think it might just be the Problem of CMS 2.7 not being updated anymore and thus being less and less suited for operation with each Android update. So I am eagerly waiting for a new version that includes firewall.
I am using Comodo products on all my PCs etc, as I like the usability and sleekness of the product. I would hate it to have to change.
So please: finish the new CMS product!
PS: english is not my mother tongue, so sorry for any misspelling. Also my editor tries to correct the english words into german so forgive any strange words or CAPSed initials ...