Yonex Isometric Tour 300. Circa 1995.
This is an addendum to my original post. I've been asked to touch more upon either (or both) of these subjects. Though that post was written over a year ago, it rings truer than ever.
When I played high school badminton for my school in Taipei carbon technologies (like graphite) were finding their way into the racquets we used. The "best" racquets were integrated "unibody" racquets where the handle, shaft, and head were all a single monocoque piece. Traditionally racquets were made of some metal in multiple pieces and then welded together. These "newer" racquets were not only lighter due to their materials but were also lighter without sacrificing structural integrity. For all intents and purposes these racquets were more structurally sound because they were designed as a single piece and not welded together. That being said, traditional welding was pretty good and I wouldn't necessarily bet on an old racquet falling apart at the welds.