Whats the difference between these Yamaha Acoustics?

So next week I'm buying a an Acoustic, and unless any suggests otherwise I'll be going for Yamaha. I trust them.
The FG720S and FG750S are both very similiar guitars, except:
The FG20 is ?230
The FG50 is ?315

So the only difference listed is that the 50 is lighter and the hardware is gold (the 20 has chrome).
Now, money isn't such an issue in this case, but I want to know if the extra ?100 or so that I'm paying is getting me anything. I expect there is more to it than just hardware and weight differences.
But can anyone help me out. Is the FG50S worth the ?100 more than the FG20S, and if it is, why??