Excited to receive this late Christmas present, I have read many good things about this watch. I originally had my eye on the maratac sr-3 but Had read that it could not be trusted in steamy conditions, and it had no date complications. Then there was the Seiko srp655 but was unsure about the 48mm size and the 4r15 movement so I ended up missing the drop. This watch has the classic look, 200m water resistance, metal strap, upgraded 6r15 with Seiko Spron spring, 44km, plus it may have been my last chance to grab one with the classic dial (without the "x"). Now I just have to wait on it to arrive. I sure hope that I don't get one of the infamous misaligned chapter rings.
ThefabeThey're all great watches. I have the sr3, sr9015 and the tuna you mention and used to own a blumo. Ironically I think the tuna is the most comfy one and wears the best. The sumo wears a little big if you have smaller wrists. In any case Tuna > Sumo > SR#. That being said they're all to large for a wrist 6.5 inches or less, excepting the sr3 of course.