As above - it's still a complex system but not terrible.
FYI - I've had the following changed:
- Heater matrix changed due to it blocking up (perfect since)
- Changed header tank at same time to one without silicant bag
- Water pump electronic widget/sleeve failed so had a `revised` version without sleeve fitted (did cambelt at same time)
- New thermostat and thermostat housing (done at same time as w/pump as didn't know if pump or t/stat causing overheat). It's a complete b!tch to get at to change.
Ref the pump sleeve - I've seen a lot of problems on a Skoda forum, so they do fail but not sure on the %'ages.
I never had my coolant fully drained or bled using VCDS - just got my mechanic to drop the main rad pipe off and drain as much out as he could. Due to a w/pump and t/stat change, most of it came out anyway. 18 months later and it's a bit cloudy in the header tank, so at the next service I'll get it drained again and refilled. Not perfect but I've never had an issue and the system is meant to self-bleed.