Thanks for your replies so far. For the LDG it is pretty clear, as for the T/O not at all. I am F/O in a european company, during my ATPL I have been told to consider it as a heavy, but it changed since. Officially it is a medium type, so for LDG I found official docs, as for T/O not yet. Personally I am timing once the preceeding is starting to roll,as it will take me +- the same time to reach the rotation point. But it would be nice to find something written regarding that.