As someone said above, it's quite a distance to get there from Aulani. It does depend on what group you have with you, if you have young kids, PCC may be more fun as there's activities for them to do, though if I was paying to stay at Aulani, I'd rather spend more time to enjoy all the great amenities Aulani has for kids than at the luau. PCC is literally all the way on the other side of the island and you'll be in a long shuttle bus ride if you're not in your own car rental.
I've done both PCC and Chief's Luau before, the latter of which is much closer to Aulani, and if you have limited time in Hawaii and want a luau experience, I'd do Chief's Luau. They were absolutely hilarious, have a very impressive fire show, and they also had some activities to do beforehand that were good for kids, though not as many as at PCC. If you don't have young kids with you, I'd definitely go with Chief's Luau.