Rhino's service rep is recommending the Gen 2 as it patterns 8% better than the Gen 1, in their findings.
As I understand it the Gen 1 has 18 ports and Gen 2 with 6 or 9 ports; however they will custom make without ports if desired, for a nominal cost. And the Gen1 I think is Titanium whereas the Gen 2 is stainless steel, but I could be mistaken on those two particulars.
While reading over the forums here it seems to me that many are preferring the Gen 1.
What are you finding to work best?