For those of you with 2009 / 10 GTI's and who have not yet changed your tensioners...
I was at my local VW indie last week having a minor service carried out, another mk6 GTI was in there, 10 plate with around 65k on clock... failed tensioner, bent valves etc. Also, a 2009 Audi A4 2.0 TFSI (same EA888 engine) in for exactly the same failure, this time requiring a complete engine replacement such the damage.
Sadly as time goes by and mileages increase, more 09 / 10 2.0 TSI tensioners will fail. I am still yet to see any real evidence of 2011 onwards GTI's having wide spread tensioner failures, some good news I guess.
If you plan on keeping your car for any length of time, IMO budget to replace the timing chain as well, read my experience on page 56 of this thread of not chaging the chain as well.
Pays your money, takes your chance...