My Hayward Phantom is on its last leg and only skims the pool surface (can’t get it to clean the floor) so it’s time for a new cleaner. Reading the recommendations on this forum, I’ve convinced myself to try a robotic cleaner. I’m surprised at how many different models are available from just Maytronics alone. Given the size of my pool and my interest in automation, I’m leaning towards the Dolphin Premium Class. But even within that class there are at least four to choose from and I can tell any differences among them from the Dolphin Website. Does anyone know the differences between these models: S300i, Active 30i, T55i, and M500? Also interested to know if buying from the web is the way to go given the current t $175 rebate on all these models. Any help would be appreciated?