There is not that much difference between a EVO3 and a EVO3'S except for some screen brightness screen and faster processor. There is a new model from Simrad base on a Android platform and very easy to use.
It's a new model so I should say to wait maybe to the next season so they can correct some small glitches; at this moment you can't use a Navionics map but maybe you don't use it's the case it's not a big deal. Depends also what you are using for AP .
You have a excellent unit with your EVO2.