Tboooe,
I too moved from the 303-300 to the 306SACD. I would love to give you a glowing review right now (which is how it would be!) but I don't believe until I get 2-300 hours I should really comment, I don't have enough information.
It just keeps getting better, dynamic, crisp deep bass, wonderful across the spectrum. What I am discovering is that it keeps getting deeper and wider, more layers and texture.
I was like you on the SACD no big deal bandwagon but unless you've got a super high end vinyl rig, this player (and I'm sure others out there) will change your mind. Redbook has a whole lot to offer when heard through this player. I will update you when I have something to offer however, it will be very positive...just a matter of how positive.
Got a very fair deal from Upscale Audio/Kevin Deal & Jared and could not recommend them more highly. I have been to their warehouse/demo room and you cannot imagine how much gear they stock. If Cary makes it Upscale has it.
What is your associated equipment?