I have been out of the photography game for a couple of years now, but I'm looking forward to getting back in. My best pictures have come from medium format and/or while travelling. I have experience in Mamiya RB and RZ systems, and previously used the RB with the 90 f3.8 and two backs as my travel rig. As you can imagine, this got pretty heavy lugging around Europe, but the 6x7 negs balanced that out. I have never used the square format, but it seems to strike a good balance between size and system weight/portability. Of the myriad 6x6 cameras available, I'm interested in the Hassy 500cm and Mamiya C330. I don't tend grow huge systems, so the most I'd be looking at travelling with would be a 500cm/80mm/2 backs or C330/80mm and 55mm. I don't have time to rent either of these systems (Hassy or Mamiya TLR), which is too bad, but I have fiddled around with both and found them perfectly acceptable. I guess my questions are... Does anyone have experience travelling with either or both of these systems? What is the weight/size difference between the two? When push comes to shove, am I just better off picking up another RB67 system and travelling with that again (please say no)? Thank you all in advance.