currently had headgasket changed with cambelt waterpump and new headboard

driving back home the car didn't feel as power ful as it did do through 2nd and 3rd gear, like there was a drop in the pull when you put your foot down?

when the car has stopped and you slightly give it some revs, you can hear the turbo kicking but then you hear a very faint 'hisss' after?

could this be a potential boost leak in one of the pipes?

Probably haven't done cambelt properly ie timing is off.

Or boost leak or associated pipes.

Agreed; a new cambelt needs a dealership computer or paid shareware VCDS to set up the fuel timing properly.

changed my cambelt in the drive no vcds ect needed sounds like boost leak to me