Chosen Solution

Is it OK to upgrade to High Sierra on a Samsung SSD EVO 860 in MacBook Pro Late 2011 right now?

You can actually install High Sierra on an SSD without automatically converting to APFS, using, of course, HFS+ instead.

  1. Download the MacOS High Sierra installer from the App Store as usual, making sure it’s within the /Applications/ directory. You will need the full installer to have the Contents/Resources/ options available to you.
  2. Open the Terminal application, found in /Applications/Utilities/ (or from the Utilities screen menu options if booted from a USB boot installer)
  3. Enter the following command syntax at the command line prompt: /Applications/Install\ macOS\ High\ Sierra.app/Contents/Resources/startosinstall –converttoapfs NO
  4. Hit return key to start the macOS High Sierra install process with the –converttoapfs NO directive, thereby skipping the APFS conversion of existing file system

Apple still has a few issues with APFS which from my understanding will be fixed in the coming Mojave release. I have it running on my systems but it does encounter delays when you try saving or copying to your Home folder if you have it linked to your iCloud account. So for starters I would not enable iCloud backup.