Sorry, not true. From a manpage for find:

       -exec command ;
              Execute command; true if 0 status is returned.  All
              following arguments to find are taken to  be  argu­
              ments  to  the command until an argument consisting
              of `;' is encountered.  The string `{}' is replaced
              by the current file name being processed everywhere
              it occurs in the arguments to the command, not just
              in arguments where it is alone, as in some versions
              of find.  Both of these constructions might need to
              be  escaped  (with a `\') or quoted to protect them
              from expansion by the shell.  The command  is  exe­
              cuted in the starting directory.
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Every time it reaches the exec it launches a new process. Your version actually launches a separate instance of /bin/rm per file processed! (Good thing *nix optimizes process creation!)

But for one-off jobs, you are right. How long it takes you to remember how to do it probably matters more than any details about how much work it is for the computer. (For mass deletes I usually write a short Perl script rather than look at find just because I know Perl very well. YMMV.)

But these performance considerations matter a lot for jobs that will be run repeatedly...