I'm a huge fan of the Casio F-91W, have two of them on my desk right now. Maybe it's just me, but for this specific model I feel like it becoming bluetooth enabled breaks the spirit of the simplicity of the model.
But hey, seems like people are excited for that, happy for them! Mine will last another 10 years without it.
I own a F-91W and would instantly buy the newer upgrade (if it had vibration alarm and notification, which it doesn't unfortunately). It is more about the iconic design than simplicity.