I'm not very familiar with the ssh command. When I tried to set a variable and then echo its value on a remote machine via ssh, I found a problem. For example,
So the two statements: ITSME=itsyou & echo $ITSME are both executed on remote host. But in the case of double quotes, variable will be evaluated first so the argument passed to ssh is actually ITSME=itsyou; echo itsme. While in the case of single quotes, no special characters survive. The argument passed to ssh is ITSME=itsyou; echo $ITSME. Understood, this is really an issue of command-line processing.