Well, the only things I can complain about with the 600h are:
Tiny boot.
There are better satnavs around.
The wooden steering wheel looks good but is hard and slippery, I've had to put a naff looking cover on it.
This is my second 600h. The first was the long wheel base model, I now have the short WB and much prefer it, although it has fewer toys, such as rear 'Ottoman Massage Chair' and drop down DVD screen in the roof, it just seems more agile and easier to park. I would encourage anyone to test drive both, if you can find the rarer SWB.
Another thing worth having is 'Follow On' cruise control. With this you set it to follow the car in front when static in roadworks etc, and it moves off and stops with the car in front. I have 'Adaptive' CC which is great, but not as good, It takes a little time to trust it to brake by itself, but I use it all the time now on Mways without concern, I just pick a car going the speed I want, 70 say, set the CC to 80 and let the driver in front do the accelerating and breaking. If I had 'Lane Assist' I would be able to read the paper. (joking)
I get 34 MPG on Mways or normal roads, so no complaints from a 5L V8.
The fastest I've been in it is 130 mph on the autobahn. At that speed the engine was unstressed and humming like a sewing machine, and the car felt totally stable and safe.