Yeah, I'd recommend using the `-p $pid` option when you can. Not just because it doesn't need to scan all of /proc, like the -c[ommand] or default mode do, but also because it doesn't suddenly start listing other processes when you're in monitor mode.

That said, sometimes it is nice to see the other commands pop up in monitor mode. For example, when the rate suddenly drops in a command that you care about then the other output will often show the culprits for you to `kill -STOP`.