On my Cambo (yes, I haul it into the woods), I use the 135mm and 210mm the most. I have a 105mm and rarely use it. I'm more likely to do close-ups than sweeping vistas. I think I use the 210mm the most, actually.
David, I was thinking of the HZX over the PTB. Will it be a big difference? I'm sorta starting to think that it won't really matter that much as the price is fairly close (even new) and the cameras don't seem to be hugely different.