Both are great. You forgot to throw a Rolleiflex TLR into the mix! The latter great for hand-holding low-light. Hassy to Mamiya the differences in handling are so huge that it's a personal choice for that. I shoot my Hassy a lot in low light but use a tripod. The Mamiya for hand-holding down to 1/15 is much better vs hand-holding the Hassy.