Not too great... We spotted cockroaches in both the actual flat and the hallway. The bathroom doesn't have any ventilation, so the flat becomes very humid quickly and creates dampness. A few of our items were broken of mould in just over a week, even though we aired out the place as much as we can during the winter and were super careful.
The water in the shower can only get lukewarm - so it feels too cold to have a proper shower.
The electricity limits are very low, so you have to decide between cooking or having heat.
The internet is OK - but on the slow side I must admit.
The location is outstanding for Ericeira but the building is quite old.
I'm not sure if it's because we came during the off-season, but it was hard to get in contact with the host. However, the staff greeting us at the property was super nice - so not too sure what to say about that.