I remember feeling enthusiastic about DC-X when it was being tested... then I read this article:
http://www.spacedaily.com/news/oped-05zy.html
I hope Elon Musk's is a different story, but landing from the outer atmosphere looks just a little more difficult that what we see with the grasshopper demonstrator.
https://www.youtube.com/watch?v=0H_cjfk5v1k
It is. Even Delta Clipper did not do what the F9R is intended to do: come straight down at terminal velocity till last few seconds.
Using a few tons more fuel could be less expensive than having to rebuild all those complicated engines each time. It all depends on how much more fuel they'll need, and how cheap they can refurbish those engines. A Soyuz-2 market cost is about $40-50 million per launch. Less than half a million of that is fuel.
The critical thing isn't fuel but the vehicle actually doing the that up & back again flight plan reliably, and
then the economics working. According to Musk & co reusable hardware ballast == 40% payload penalty. The plan is to make dry mass pay itself off to the point that fuel, which is currently in the costs noise, is actually one of the major operating costs... IOW like it is for airliners.
The other way round: imagine if airliners were single-use. Thrown away after each flight.
Rubbish! It landed on exactly the same spot it took off from. What use is that? 
They'll do it soon enough, probably with Grasshopper 2 that's going to start flying from Spaceport America not too long from now (the current FAA height limit at the Texas pad is right around this latest test flight's max alt; SPA's limit is supposed to be way higher and Musk & co mentioned way higher alts for upcoming GH2, in the k-ft's.. also IIRC Musk said they'd go hypersonic with GH2). Not long (but not too recently either) ago the NGLLC race had Armadillo (Carmack & co) and Masten and others making lots of from-scratch progress doing this: flying up and translating, and back again, etc.
Then a few years later SpaceX decides it's not just flying conventional expendable rockets the way ULA etc have been for decades, but will basically fly upscaled Xombies. Another fun parallel is the way (IIRC) Armadillo went from initial all-thrust return flight to parachutes, and SpaceX initially experimenting with chutes but eventually settling on all-thrust e.g. Grasshopper.
http://www.spacedaily.com/news/oped-05zy.htmlIs this guy really saying Skylon's a particularly bad design... Really?
And then he tongues Griffin.
No wonder..
Space Cadets frequently claim that new materials like Al-Li or carbon-fiber composites as solving the weight problem, but they don't represent enough of an increase in strength/weight to make up for the massive increase in structural weight that wrapping an entire rocket stage in a heat shield implies. The DC-X was rebuilt as the DC-XA with composite propellant tanks, but its fuel fraction only went up to a pitiful 54%.
This article was written in 05. Almost a decade ago. Which is nothing considering that a decade's the ballpark for greenlighted projects to start bending metal/flying. So, less than a decade later:
http://www.nasa.gov/content/nasa-tests-game-changing-composite-cryogenic-fuel-tank_marshall_news/#.UdOfqPnQlc4http://www.aviationweek.com/Article.aspx?id=/article-xml/AW_07_08_2013_p18-592556.xmlAnd of course Skylon just cleared proof of concept for the biggest obstacle-item (pre-cooler), and should be doing actual full (whole assembly) SABRE practical proof either next, or soon in next few milestones.
In flight the intake air will go to -140C in milliseconds. A serious step for aerospace tech.
No pilot
Reaction Engines is doing their best to stay out of government funding. Delta Clipper...
