Piled foundations are used when the ground cannot support the weight of the building.
Sometimes they are used when the ground is subject to subsidence, either because it is made-up ground or landfill (watch out as there could be methane gas in landfill!) or subject to shrinkage or heave (clay) and/or where trees are or were.
You could say that the worst case scenario has been taken into account.
On the other hand you could also say that the ground is dodgy and whilst the house may be alright, there could be associated problems and issues in the future, regarding under ground drainage pipes, gardens, drives, paths and patios all subsiding!
Piled foundations are generally more expensive so would not be a housebuilder's first choice.
So both good and bad points.
The main thing is that new homes are badly built!
They are overpriced, small, dark, cramped and difficult to sell on.
When you have problems, house builders don't put things right.
I know of one buyer on this forum who still has major issues seven months after moving in.
He has had to take 38 days off, so work could be done on it since moving in.
In addition a survey suggested that 75% of buyers would not even look at a home built after 2003.
Finally, now is the absolute worst time to buy another home.
It is the top of the market, the bubble is about to meet its pin!
It's all about making things look good for next years election.
Buy in 2016 and you will get the same property for 20% less than it is now.