Re: Maybe he should have licenced a SABRE engine
..and Sabre in it's current form is not intended to cope with anything big. *IF* SABRE flies and is successful THEN they may start to look at bigger and better. As it stands, even in the 2 stage to orbit scenario, we're looking at fairly small payloads.
I'm rooting big time for SABRE. A Skylon space plane and a SpaceX reusable heavy lifter might well be an interesting combination, ie big truck and a family car. Same journeys, different jobs.