My first post!
(Caveat - just my opinion to add to the debate!)
I have to agree with the majority of comments and I'm actually very surprised that anyone would be thinking brakes needing replacement is an unusual thing at 70K.
I've owned all sorts of cars in my time (12 in total) and there are some key things that have come from that -
1) Every model from every manufacturer has it's "things", i.e. a weakness in some way that is very common. The advantage of forums like this is that you can become aware of them and from that gain two benefits - you either replace these things before they inevitably fail, or you wait for them to fail but take confidence from the fact that when they do you know exactly what it is and the best way to resolve them - e.g. replace with new or perhaps uprated components. Key example for me was the control arm bushes on the BMW E46 Coupe - I knew they would fail (and they did at 38K miles), the steering went all over the shop so I knew that I would replace them with powerflex bushes - I'd already downloaded a handy guide I found online and did it myself.
2) Brakes and tyres. Some of the mileage I've seen quoted I was thinking the opposite to the original poster - I was amazed people got that much out of them. Perhaps your car history makes a big difference to how you think about these things. A number of my cars were hot hatches, great fun, but in particular the Clios (I had 4) I had would get through front tyres every 6K, front discs and pads at 18K, the exhausts began to rot from the inside at 30K and the rear shocks went at 35K.
So, when I look at a car the size and weight of the 159 getting 10s of thousands of miles from its tyres and brakes I'm really pleased with that. 70k from brakes seems like crazy talk from what I'm used to!
It's actually my wife that owns the 159 but I love it too even though we've just had to replace the clutch and flywheel. What I will say is that my car is a BMW 3 series with only 22k on the clock and I've had two very expensive failures of non-service items and I'm going to book it in this week for yet another running problem. I've also had to buy a second set of wheels with winter tyres because it literally will not move from our drive even with the slightest sprinkling of snow or ice. However, these are things I accept because that's what I have to pay to run a car like that.
So, hopefully this helps the original poster decide whether they are still happy with the car - just think, it could be worse, you could have a french hatchback that eats tyres and brakes more often than it has a service!