Hello, we put ours into our self-build 11 years ago (muse, I am interested in your posts!). Ours is Villavent and I love it.
Our cooker hood does extract separately, to outside - we have a kitchen / dining / living room and so we wanted a good extraction system. We do extract heat from the rest of the kitchen area.
We have: solar thermal panels, photovoltaic cells and the heat recovery system. I love them all, but if forced to pick one, it would be the heat recovery / ventilation system.
We have neither ground source nor air source heat pumps. When we built, the co-efficient of efficiency was not good enough to warrant it. However, with our underfloor heating system, we are well placed to install an air source pump when the time is right (our ground is not very suitable for ground source)