Not sure where this fits in this thread, but from personal experience I'd think carefully about re-mapping.
My last car was a 2005 GolfV GT TDi (140 Bhp). I had it 'chipped' to 170 Bhp and the results were outstanding in the short term. It was pretty rapid and the car seem much smoother and more economical too.
Within 1000 miles a load bang and severe vibration occured under accelleration... turnred out one of the cast engine-mounting brackets had sheared causing the engine to drop on one side. Luckily this was replaced under warranty. I was crapping myself incase VW investigated the cause. Perhaps a little paranoid?

Then after another 1000 miles the turbo became very noisy once the engine was hot.

I then decided enough was enough and I part-exed it for the GTi

So, short term = big yes, Long term = erm???