which one should I buy?

All I can say is that in my experience the NAV system is great. Very easy to use and very clear large screen. You will not get lost. Because it is hooked into the car's computers it even navigates undergound when the sattelite is lost (in Sydney there are lots of tunnels).

As for the airconditioning, I never turn it off. Set at 23 C and forget. I still average 4.8 litres / 100km (48 mpg I think).

Keyless entry is also fantastic and the stability control really works. The blue tooth phone is very handy and clear even though the voice commands get confused sometimes with background noise.

I hope this helps.

 

While Shieldsy has a full option Prius, I am at the opposite end, just a basic model. Mind you, my basic model has a few things that the US basic does not have, but.....

The comments that I have heard on the US version of the NAV is that you may be better off buying an after market Nav. Other than that, I would recommend going for as much as possible, if you can afford it. The number of nice things in this car sure do spoil you.

 

I got the fully-loaded USA 2005 model (about 31k$), and have never regretted it.

Yes, the navigation system has its issues -- but I've been able to compare it to my wife's late-2006 Garmin Nüvi, and it's not really that much worse. (The 2006+ models have an improved UI, at least in everything other than Nav, and higher res regardless.)

My view was similar to yours -- I buy a car, and drive it into the ground, usually over 10 years or so. Buying the best I could afford at the time made sense to me, and I'm pretty happy with that decision. There certainly are issues -- the Bluetooth worked better with my Verizion Motorola V710 than it does with my AT&T Apple iPhone; the nav data (even on the 7.1 update) is still out of date); I wish it had the backup camera -- but overall it's a great car.

Good luck with yours!

 

Apparently the most important thing to do when shopping for a new Prius is move to a country that has a height adjustable seat!!

Seriously if you live where the roads are slipery get stability control, if you travel around get the GPS and blue tooth, if you like a car to handle smartly get a touring version but if you want it to corner like it's on rails fit the TRD Sportivo suspension which isn't a factory option but if you go this way no point getting a touring package. You can then go with Volk Racing light weight wheels.

Don't forget now, height adjustable seat.

Oh, and silver is the best colour.

 

If I were allowed only one option, it would be the Vehicle Stability Control.

Having played with it in an icy/snowy parking lot, I KNOW it works!
I will not buy another car without VSC.