Macrium Reflect Free is pretty much a bare bones image backup & restore app, but for many, myself included, that's all that's needed or wanted. It's faster than many, but you won't usually notice a difference when it comes to results using Macrium, Paragon, AOMEI, EaseUS etc. It does leave the added partitions that you get with win10 alone, not messing with the boot files for example like some other backup solutions. Restoring those partitions from a backup, Macrium can however give them a drive letter in Windows, which you'll want to remove [Control Panel -> Admin Tools -> Computer Mgmt.]. For GPT partitions the GUID type stays the same as the original, e.g. a Recovery partition is still a Recovery partition when restored.
Maybe Macrium Reflect's biggest claim to fame is its USB sticks, which seem to work everywhere, where often alternatives will not. Some apps have you download part of or the complete Windows ADK before you can create a bootable USB stick. While that's still an option with Paragon's latest & Macrium Reflect, by default they'll use the win10 recovery files that are stored on the Recovery partition, assuming you have both win10 and its Recovery partition. That Recovery partition can be deleted to get the 500 MB it uses back, the only consequence being you won't be able to use win10's recovery features. If you don't have that partition, or win10, I've successfully created those bootable USB sticks in a win10 VM that had the Recovery partition -- it just needs those files, wherever you have or get them.
If you want/need to restore the Windows partition from an image backup, the best way in terms of speed is to use a bootable USB stick, but it's not necessary. If you start Macrium Reflect free in Windows, then have it restore a backup of Windows, it creates everything that would be on its bootable USB stick, but it puts them in the C:\Boot folder that Macrium adds when it's installed, and adds those files to the boot menu. When you restart, those files are read into memory [on a RAM disk], and the partition is restored. Because those files weren't there originally, when you created the backup, they're gone once it's restored. EasyBCD is an easy way to delete that choice if it was added to the boot menu, and you can also turn that boot menu back off. You could of course add those files to the C:Boot folder before you perform a backup, and they'll be there after it's restored. Why is a bootable USB stick preferred? It can take a while to add those files to the hard drive, and it's just faster if you have that USB stick in hand already.