Hi there, I have the option of flying either AC Signature Class or UA Polaris on a one-way ticket to Auckland. Based on some videos I have watched, it looks like the AC seat is slightly roomier? It also looks like the amenities with UA are better.
The seat size is probably my primary concern because I am 6'4. I have been on AC Signature before and found it to be sufficiently roomy.

Hoping those that have tried both can give me a run down of pros and cons.
Thanks!