Plugging the Tesla into a SuperCharger or the i-MiEV into CHAdeMO reaps the most benefit from such high power charging if the car's battery is at a low state of charge. On longer trips, this results in significant time savings if one simply keeps the charge state low and charges just enough to get to the next charging station.
Of course, this runs counter to our normal good charging and driving habits of always leaving a nice safety margin at the bottom.
Had an interesting episode while driving the 400 miles (640km) up from home to Medford Oregon yesterday: I had charged in Corning (still in the valley, basically at sea level). The next SuperCharger is in the city Mt. Shasta at around 3600' (1100m) and recognizing the altitude change I had put in just a wee bit more than necessary to get there.
So there I am happily zooming along still trying to figure out the latest Tesla over-the-air Media update when I get a phone call from my wife: "I see you've passed Red Bluff but could you go back there and meet someone at a gas station to retrieve my brother's camping gear?" - he had just completed a 100-mile canoe trip and forgot some of his stuff. With her iPad and the Tesla app, my wife knows EXACTLY where I am with the Tesla (works both ways).
"Um, ok" - so I take the next turnoff and go back about 15 miles and meet this nice couple and chat EVs (he'd never seen a Tesla before but is really into environmental stuff) and we say goodbye and I now have 30 more miles to go than previously. No worries, just slowed down a bit and arrived in Mt. Shasta with 10% SoC (predicted 8% when leaving the gas station in Red Bluff).
Moral of the story: ALWAYS have a range cushion.
A quick glance at PlugShare shows that there were still plenty of J1772 stations and campgrounds along the way, so there was no danger of running out of juice - and I never leave home without my huge box of adapters.