If I didn't have a 6500, I'd be tempted but can't see the value in only upgrading a bit. The throat is great and like the needle down feature too.
Enjoy the 6500, but also have 6 older Singers as well. (I like the Touch & Sew models where you don't have to remove the bobbin to rewind it. Also like the bobbin because you can unscrew it to get rid of thread you don't want.)