The reason I never use Heredoc is because you need to abandon your indentation, otherwise your tabs/spaces get included in the string. Is there a way around that?
I've gotten into the habit of generally using single quoted strings (with 'around them') which alleviates most problems with escaping double quotes. And for the odd string that needs to have a single quote inside I switch back to double quoting.
This approach also has the added bonus of stopping PHP from accidentally evaluating something inside the strings.