I have a Peugeot 406 Estate 3.0 V6 - the uprated 210 bhp 2000 model. It's certainly fast and really finds its legs on German autobahns, easily reaching twice the UK limit. However, the handling lets it down if you push hard into bends on UK roads, and if you cover a few fast miles, the otherwise excellent brakes fade rapidly to nothing as they simmer gently. This won't happen too often, though, as you'll be far too obsessed with fuel consumption. I see 25 mpg if enthusiastic, but a reasonable 32 if I drive like a nun.
The cabin is roomy and very luxurious, with leather and walnut and enough toys to keep even my gadget-orientated mind busy. It's a shame they added an electric sunroof to the 2000 model, though. Since I have the climate control to keep me cool, the only thing the sunroof adds is wind noise and rattles from the blind and headlining. Trips to the dealers have simply made these rattles worse. In fact, the only real problem with the car has been Peugeot's dealer network. They seem unable to fix any problems reported and leave the car in a worse state than it was before.
So, apart from minor problems with rattles and trim - oh yes, and a gearbox oil leak - I've enjoyed the past 10,000 miles. It's a reasonably fast and comfortable estate, spoiled only by the dealers plus brakes and handling that are not quite the match of the wonderful 210 bhp V6 engine.