Rob,
I had the Dolphin Premier and what they say is all marketing..

Pretty much total Bull Feathers..
Let's make sure we are on the same page.. Please show me a pic of the 'Premier' that you plan to buy.. I ask, because my Premier was an older design when I bought it about 8 or 10 years ago... I want to make sure the we are talking about the same robot...
If it looks like this...
View attachment 645433
It is older than dirt... Half the robot the EVO is..
That said, I used it for 5 or 6 years and it works, but just not near as well as my EVO.
The EVO costs less, has a better cable, a better top loading basket, etc, etc..
Buy whatever floats your boat..
Edit... If you just want a Dolphin, but the S200 style.. Even that is better than the older Premier..
Thanks,
Jim R.