My wife had a drive of the Autocar Prius this week while her (our) BMW Z4 was in the shop. "Super-boring car" was her three-word review. I found that assessment harsh but, honestly, I'd started to have similar thoughts myself as it approached the 6000-mile mark.

The latest Prius is designed to do one thing: be as efficient as possible. This is something it is very good at. But, like most things that are designed for one specific purpose, it can fall short in other areas - in this case how well it drives, especially on longer-distance journeys.

An example of familiarity breeding contempt, perhaps. To get some perspective and see how much progress the Prius has made over the generations, I spent some time in a Mk3 car.

Like so many other Mk3 Priuses, the car had lived its life as a taxi, racking up almost 300,000 miles in the process. It wasn't a ratty old car, however. Quite the opposite. It was bought for just under £3000 by eBay, which then used new and pre-owned parts from its own online marketplace to restore it.

Those parts (worth £1865) included new tyres, brake discs, pads, lights, floor mats and seat covers - even a new steering wheel. The result was a car that felt well loved rather than well used.

My first impressions were that our current-gen Prius is far better-looking than its grandparent, but that the Mk3 is more practical, despite both cars having almost identical dimensions. The old car is notably easier to enter and exit, thanks to its less raked shape.

Inside, the Mk3 has a much more quirkily designed cabin than that of the current car, one that very much captures the 2009 zeitgeist. Regardless, I could see how the older model informed the new one, with their shared focus on physical controls, plus a similar drive selector layout, raised centre console and digital speedometer that sits just below the scuttle, acting like a faux head-up display.

One thing did throw me, though: the foot-activated parking brake. I've driven many cars both old and new but have never come across a post-2000s car with one of these. It felt a bit like the controls had been lifted from a ride-on lawnmower.

On the road, the old Prius put the new one in a much better light. It felt heavy, it handled a bit like a boat and the powertrain (a 1.8-litre petrol four plus an electric motor) really struggled when an incline became more than a modest slope.

In more city-focused situations, the Prius felt more comfortable. For example, its EV mode came to the fore at speeds of up to 30mph and offered around 11 miles of engine-off range, although it actually seemed like more. Combined with the good provision of space inside, it was easy to see why this car was so popular with cabbies.

However, as Joni Mitchell had it, you don't know what you've got till it's gone. Back in the Mk5, everything felt much more premium inside, while the new car's powertrain and driving composure were considerably improved.

Yes, the new Prius costs nearly £40,000, which is premium price territory, but that shows how Toyota now views it - and, having experienced how far the hybrid has come in the past decade, I can understand the reasoning. Maybe it isn't such a boring car after all.