I will pile on here and say that the jersey boy speaks the truth. An ounce saved out of the tail saves another 3 oz more or less (often more) out of the nose, for a total savings of 4 oz out of the all-up weight.

As for the MK bellcrank, I got two of them a couple years back, just to see what all the jabber was about. I put one in a plane that needed weight in the tail, and in that application it worked OK, but the other one still sits in its package. Go to the same Central Hobbies website and look up their Dual Elevator Pushrod System (somewhere in Technical Tips). I've used variations of that system on the last few planes I've done. It is a great weight saver, and gives very precise control with a single side-mounted elevator servo