After a lot of soul searching and research I just purchased a Mamiya RB67 Professional SD. I have been shooting with the Mamiya m645 for almost ten years and was no longer enamorred with the 645 format and wanted a larger negative. You can't just point and shoot with this camera and that suits me as I rarely go hog wild and start burning film anyway. I have the camera in for cleaning and will have it in my hands by the end of next week. In the mean time.... ...I would love to hear from anyone who uses this camera concerning its idiosyncrasies. Every camera system I have used has its dos and don'ts. And I think, from reading the manual, that this camera has some critical dodon'ts. If anyone would have the time to fill me in on any phase of their experience with their RB I would love to benefit from learning from them.