If you really want ease, reliability and super performance, Tunze skimmers should be on your list. I have not used an Akula, but Tunze crushes the other ones that you listed in every category. So does LifeReef - which is probably the most chill skimmer ever made... just works with no fits or fusses and you can use any pump that you want with it.
Yes, skimmers are better than others in both build quality, performance and longevity - the bodies usually last, but the pumps and parts can be hard to get later on. Even though I don't think that RO skimmers have been all that great since they stopped using Sicce PSK pumps in them, they do still have parts and warranties, so this is good for Coralife and RO. For the smaller brands, look to Vertex as a warning... they are out of buisness now and people have bodies with pumps either broken or waiting to break with only hope being a retrofit of another pump with some modification and unknown performance.