I've got both and they're slightly different things.
Netflix has a wider range of film and TV (and a far better interface that does things like automatically select the best version for your display), but Prime video is effectively a freebie that goes with the delivery, having said that it has some very good original content of it's own, things like sport and music, and some different materials.
Probably the biggest complaint I have with Prime video is the UI, and the fact that if you do a search for something it'll potentially give you 3 results for the same thing in SD, HD, and UHD, often with the UHD well beyond the the first result so you end up watching the lower res version (until you realise then have to manually tell it what episode to start playing the HD or UHD version at).
Netflix has a wider range of film and TV (and a far better interface that does things like automatically select the best version for your display), but Prime video is effectively a freebie that goes with the delivery, having said that it has some very good original content of it's own, things like sport and music, and some different materials.
Probably the biggest complaint I have with Prime video is the UI, and the fact that if you do a search for something it'll potentially give you 3 results for the same thing in SD, HD, and UHD, often with the UHD well beyond the the first result so you end up watching the lower res version (until you realise then have to manually tell it what episode to start playing the HD or UHD version at).