18kg is a good weight.. but you also need to look at the spec.
That spec on say an Orange 224 (yes probably the lighter end of the scale frame), id say would be around the 15.5kg mark.
Flow rims are a super lightweight rim that most riders wouldn't want to use as an everyday dh rim. Same goes for air shock.
Id say a regular build with spring shock, 721 rims, Boxxer Teams etc would easily be over the 19kg+ mark.
Im more interested due to the suspension design and lack of weight around the rear wheel etc. Also the lack of chain slap would be a bonus too. Would be a nice quiet ride.