I have now taken the Prius for about a half hour spin with my Mum as co-pilot and as 'instruction manual'.
Drives like an automatic Corolla really. Pulls very smoothly from start and if you are accelerating a bit the engine will kick in before you get to 10kmh. Sound proofing is pretty good so it is not much to notice the engine - a good soundtrack would hide it

.
I drove it from the parents house down some 50km back streets and then onto the Nepean Hwy which is an 80 zone. It kept up with traffic fine and pulled ok from the lights to keep up. I floored it a couple of times and the little 1.5lt engine starts to sound a bit thrashy.
Did a bit of driving in a carpark with the 'stealth' mode engaged. This is a button that you push to force the car to operate soley as an electric one. Designed for quiet entry/exit from home and no exhaust driving in garages and carparks with confined spaces (and air). It turns the engine on if you floor it - I guess it thinks that there is an emergency and gives you the power back.
For everyday driving, like what Mum does, it would be great. I know most of you boy racers in the Sportivos would find it a bit sedate, but I guess that 99% of the drivers in town wouldn't notice.
I'm going to see if Mum will lend it to me and my girlfriend in a few weeks when we go to Apollo Bay for the weekend and drive the Princes Hwy past Geelong and do the Great Ocean Road. I am keen to see what it is like on a long stretch of clear road.