I actually liked the floating feeling, especially on a new smooth highway in my area. Felt like I was flying or gliding. I ran the tires at 44/42 and ended up going on a 15 or so mile dirt road on a camping trip and that ruined the ride quality. Feeling every bump and crack now. So I am going to replace the dampers (shocks and struts). Ordered Koni FSD dampers plus strut mounts. They apparently improve handling and absorb bumps and rough roads better than the stock dampers. We'll see if they have the floaty feel or a more connected feel.
I run 44f/42r on my 2015 persona w/ the stock 17"s without issue. Feels very planted. I run a couple pounds less on my wife's v three just so the ride is not a jarring for her. When I had my 2013 three liftback I ran 48f/46r. Almost maxed and again w/o any issues.
Just got a 2015 and I was wonder about t h e rear sway bar. I don't notice any floaty feeling but then my other car is a Tundra so maybe that the reason.
I realize this is an old thread, but I wanted to share my experience. I have the same feeling in my generation to Prius 2008 model model and I use text stream and I zero point reset the power steering and the problem disappeared. The only trouble is it came back a few weeks later Now I’m trying to figure out if it’s the power steering module or the power steering motor but it’s definitely loose speed as in there is too much power steering assistance when I’m on the highway