Post a picture of your current bike.

With bikes that old, the main thing is the condition. Components in good condition will be better than better components in bad condition. Given that your current bike has already been tuned up, I'd be surprised if the GF was actually better. You can pretty much assume the fork is totally shot, and you'd probably be better off with a rigid fork.

The GF might be a pound or two lighter, but without seeing both bikes in detail, it really hard to how the GF would be better.