Good question Gray Beard,

A couple of reasons for the larger counter balance -

First, because I enlarged the rudder area, the larger counter balance should help in making the rudder servo work less.
Second, because I think it looks better.
Third, mainly because I can't leave well enough alone!

It's the Great Planes 60 size Extra 300S - here's a link http://www3.towerhobbies.com/cgi-bin...?&I=LXJ580&P=7