This thread was semi-timely for me, so thank you for starting it. I recently acquired a Mamiya RB67 for cheap, and have shot 5-6 rolls of various film with it. I really like how the big negatives scan but haven't got 'round to printing. Reading this, I got off my duff and brought my darkroom back to life last night. My Dektol was brown but it still worked (the powder was, I mean, I try and keep the bag airtight and only use what I need for a print session) and after 3 misprints I got a nice image to hang and dry, and I was only up til a quarter after midnight. Ah the joys of a non-light-tight laundry darkroom.
What an amazing machine, that RB67, and a lovely print of an old steam engine. Thanks for the prompt to get me going!