where is a good balance point on a 7' spinning by new legend elite balances at about 3" from the center of the reel seat, Is that good or should i shop for another reel ?

  PS the reel i have is a pfleuger supreme magnesium.

That's a question that only you can answer.... it's purely a preference as to what is most comfortable for you.  If I were you, I'd just attach a lighter and heavier reel (than you have now) and see how each feels... then go one lighter or heavier and see if it gets even better.  You'll have a preference, one way or the other, once you start.

As flechero stated it is mostly a personal preference thing. But when I build a spinning rod for a client, I always use the reel that he/she is most comfortable with, and mostly use a slight tip heavy balance point. The anglers have found with that type of setup,  they can pinpoint their casting accuracy easier.

Just my .02¢ from the rod bench.

Good Luck & Tight Lines!!

i balance all my rods so that the rod is balanced right at the center of the reel.i use balance weights to do this.

Just like the two rodbuilders above, I have experimented with rod balance. At first I sought to balance the rod at the center of the reel (neutral balance). It feels great holding it in your hand, but actual fishing revealed, to me at least, that a little tip heavy was just right. As ReelMech stated, a little weight forward was needed for control and accuracy. It's kind of like holding a baseball bat backwards, it feels light and swings easy but is very awkward to hit the ball that way. As everyone has stated, it's a preference thing and now you have mine.

Ronnie