A couple weeks late (hey I was on vacation) but I think I saw "near" the best and worst of Polaris earlier this month for my fiancée and my anniversary trip. (SFO-FRA).
Pros: ORD Polaris lounge generally, and the Blue Door Burger specifically were much better than I anticipated. My brain still has a hard time coping with not having a check to settle.
Cons: 3-class 763 ORD-FRA -- aside from the 3 hour delay for maintenance [where they kept us on the aircraft and squirted far more deicing fluid at a control surface than should be necessary in 40-degree ambient temps], flight attendants might as well have been working a domestic economy cabin, no sense of excellence, no real polish. Of a bit more than a half dozen Polaris flights since the launch this was the first time that the purser/ISM/whatever they're being called this week didn't stop by and introduce his/herself -- and actually, come to think of it, I don't think my name was used once during the flight. Asked not to have the appetizer (fish), FA confirmed that it wouldn't be served, yet they still brought it out.