Aero beats weight every time
I’d not class any of those wheels as aero.
If your after a decent set of wheels for training then either of those will be fine and will feel quite a bit different to the Giant ones, mostly due to less weight. They’ll just feel a bit quicker as they’ll accelerate that bit quicker. I might go for the Hunt because I could easily source replacement parts, or I might go for the Mavic as they look a bit nicer and they’re apparently very good tubeless.
Properly deep section aero wheels (50+ mm) you need to be going quick to get the benefit, and the faster you go the more benefit you get. Also if you’re not going quick then they can be a handful. Pootling to the start line with an 808 (80mm) on the front of the TT bike on a windy day can have me wondering if I’ve not made a big mistake, but once I’m up over 25mph it’s usually very stable. And as TiRed said, on a windy day if into a headwind you want every bit of aero gain you can get.
For amateurs I bet aero makes little difference.
Depends what you’re amateur at and what you categorise as a difference I guess. On z2 training rides if I go from my normal training wheels (which are a bit like those Hunt ones) to a set of 404 then my average speed on rides goes up about 1 mph.