With GameSparks realtime being able to select regions for their "servers", what's the point in using Gamelift? Is GameSparks realtime using P2P, and GameLift is using dedicated servers?
I understand there are a suite of tools that GameSparks has that GameLift does not, but I'm specifically speaking to the difference in the realtime server hosting of both.
GameSparks realtime is limited in that you can't do complex authoritative collision detection or AI calculation.
That is where Gamelift would come into play allowing you to upload say a headless unity exe that does all the collision detection and AI calculations.