I'd go with Polaris. My experience in Centurion over last 6-9 mo has been that the food is borderline inedible and, depending on time, lounge is jammed. Polaris food isn't great, but depending on the day I'd say better and the restaurant area is definitely better if timing works out for you (e.g., there's not a long wait). Wines at Polaris are definitely better, cocktails probably on par (but not relevant in your case). I'd also give Polaris edge for crowds, though that one is somewhat variable.

They are < 5 min apart post-security so easy walk between the two