I've had both & I would say that the bluespots in general have more spunk than the yellow heads. They will eat fish. One of mine ate a yellow clown goby right in front of me!
6-lines can get aggressive & when they do, they might not be good tank mates for any jawfish. You don't want it harrassed so that it feels like it need to relocate it's hole. This will cause stress which in a bluespot will lead to disease & death.
My last bluespot jumped when my cat put a paw on the tank, he never fully recovered and finally died.
As Texas Aggie 06 said, cover you're tank, one person put it well when he said that "maybe not today or tomorrow, but eventually this fish will jump from your tank"
The yellow heads, though also jumpers, are a little less jumpy than the bluespots especially after established.
Oh, BTW, did i mention that bluespots are jumpers?
