I am seeking folks experience with the use of Lens extension tubes and or Rear extension frames found with some camera makes. How does this effect movements and general usability. Are they a poor option against getting a camera with longer bellows range, if one could?

While on the subject, what do photographers feel about tele lenses, generally. A last resort to gain length and or weight saving or a genuine love of the design. How is this rationalised against loss or difficulty od movements.

Otzi