Been using the Free version myself for years, On my own PC's they back up automatically every day to Servers in my workshop, as well as a few other files to online storage.
Do have a older Paid version as well (V7) Server edition.
I normally use the bootable CD on Customers PC's to save an image and recover data , or in most cases unbootable PC's images will boot Via viboot.
Macrium does have one feature that MANY others don't -- If a image wont boot on putting back theres an option to fix the boot problem.
"WHEN" the time comes I'll buy it, its been a LOT more reliable than the others.
Tried them all really, AOMEI Backupper, ToDo, Acronis etc, ALL have failed at various times.
What a LOT of people don't know is while they say their backup is working fine, But is it really ????? Have they actually been FULLY Tested. Meaning put in a blank drive and drop the image back so it will boot back to a working system ??? I know the answer, and its NOT yes
Seen countless times people think its working and when its actually needed it fails. MANY back up programs will back up data , which is fine, but not all will create a whole snapshot of the PC.
Meaning -- lets say a hard drive fails - The backups they have been doing may have backed up data BUT that on its own is useless. You still have to install the OS, put all your programs back, reset up accounts, alter settings to how you like it, THEN put the data back.
With Macrium - I set it so in the event of a drive failing it takes roughly 20-30 minutes and fully restore, up to and running with everything exactly how it was.
Basically use Macrium many times a week on various computers without any problems.
Once a customer was using Acronis, thinking they were backing up and data was safe. Their Drive spat the dummy and on trying to put the image back it failed big time (around a month of backups) totally failed due to corruptions. Couldn't recover the data either.
Contacted Acronis - They basically said " its not their fault, its tough luck the person should regularly check to make sure the backups worked BEFORE they were needed'
Just last week, A customer has AOMEI Backupper installed, so made an image using their software, it was only a precaution and imaged the computer before upgrading hardware , dropped the image back onto a spare drive-- Damn useless -- Wouldn't boot, half the data that was there in the image couldn't open, they had NEVER tested any backups either. In fact AOMEI even warn that the images may not boot and link how to manually fix it -- Yeah didn't work either.
So back to original, if Macrium go to fully paid so be it, I'll stick with software I know works, still a year away anyway.

Nothing is 100% perfect but some are better than others.
Upgrades = Old bugs replaced with new Bugs.