ECO mode with Cruise Control?

Sure. Eco mode has nothing to do with whether you use cruise or not, they are separate functions.

 

I've noticed the cruise control's 'attitude' is aggressive when it senses you need more throttle while cruising. For example, when cruising along and I come upon a slight incline in the road, the cruise control will over-throttle to overcome it, then under-throttle when I'm coming down off the backside. This kills your mpg. I've owned may cars with cruise over the years and several behaved more appropriately. They would gently apply throttle to try to maintain speed, only to apply more and more throttle if it was not able to hold speed.

Too bad Toyota didn't get this one figured out.

 

I don't notice either adverse behavior or outcome with the 2012 Prius v Five cruise control, which is quite progressive in its response to load changes, whether in ECO, <Default>, or POWER mode.

 

I think I follow your reasoning. I have not been pleased with the cruise control logic in our Corolla, my dad is not pleased with the cruise control logic in their RAV4. It is too "aggressive" if the speed falls, and overshoots. Our '12 Civic works beautifully. I was hoping that our new (to us) Prius v would be more "non-Toyota" like. I haven't tested it yet, but am hoping our experience will be like Air_Boss's.