Got a chance to throw a few games with the Super Natural (SN).
First, don't be fooled with this "hybrid stuff" regarding the SN cover. While it gets through the heads clean and makes a controlled move off the dry, it's still a Urethane ball. It reminds me of a slightly more aggressive version of the Brunswick Avalanche for a direct comparison.
I haven't thrown a Tank, but my guess is that the SN is longer with a more pronounced move off the dry. The Tank RG and unpolished NIB cover will pretty much dictate that difference.
Back to the SN, I'm thinking it will probably be the most useful Urethane I've thrown. I've owned most of the modern era Urethanes (dull and polished), and my initial thought is that the SN will be the most versatile. I'm looking forward to using it on a shorter tournament WTBA pattern next weekend.