The GPS is moronic. First of all, it does not know the toll roads. I set it specifically to avoid tolls, and it takes me to them without any indication it is a toll road. The funny part is taking a toll road sometimes adds miles to a trip. I have seen it adding as much as 30 miles only because it would want me to take tolls. It does not know how to take local routes. I sometimes select to avoid the highways but no matter what I choose in most of the occasions it takes me to a nearest highway instead of staying off of it. Short or alternative options usually only differ at what point I exit a freeway. Other complaints: I rely on voice directions as I keep my eyes on the road. Caught it number of times saying left and showing right, and opposite. Occasionally would not prompt to exit a highway. My previous Prius's navi did not do any of this stupidity. Very aggravating.
I also have a 2015 Prius 3 and I also find the GPS to be lacking. I tried it and few times and found it to be (what I thought was) unusually hard to program. My wife has a 2013 Nissan Rogue and I have similar complaints on that one. I have found it much easier to use Google maps on my iphone
Gen2's was better than Gen3's in my opinion. (Also Gen4 > Gen3.) My wife's Gen3 is defective enough that we're getting it replaced just under the wire for the 3/36 bumper-to-bumper warranty. We have video of it claiming we were facing the wrong way going 60 down the freeway; no way we did that in reverse.
Gen3's are not all created equal. There's Gen3 before Entune and Gen3 after Entune. I preferred the Gen3 software on the 2011 to the 2014.
True, there is also basic vs premium nav. My comments were related specifically to the 2013 premium HDD navigation system; I believe it includes Entune.