So the turbo wasnt worth it on the 2.5?
I have a 2.5 and was thinking of running the turbo for future purchase
That all depends on your definition of "worth it".
There aren't too many mk6 turbo builds. And the one that I do know of... he said that initially he ran into a lot of issues and it ended up costing upwards of $8K.
However, if you can deal with that, you have money, and possibly a secondary car...then you can potentially have a platform that makes stupid power.
You can hit up thegreyt for more info. He has a mk5 2.5 turbo build and I know he's running without much issue right now.