As a general rule of thumb I try not to add unnecessary weight to models, however sometimes functional additional weight from say a larger engine or heavier batteries can improve the way some models behave in certain conditions. For example my Goldberg Extra at 10.25 lbs with a gas engine grooves so much better than when it weighed 8.5 lbs. with a .90 size glow engine. But then the CG Extra is really a stand out from the crowd and almost a one of a kind well mannered flying aircraft.

Karol