Hey all; I'm new to the forum and just read this post.
To answer the original question: I recall the FCC had a hand in the reason why the TG-16 is so much bigger. Something about the larger casing putting out fewer waves of interference.
I'm not 100% sure on that (I am going back over ten years in memory) but I believe that's the same reason why so many cool electronics and gadgets never make it to the U.S.
- Del