Resently a comment on the Landley HL-20 came up. the writer via a AIAA document stated that he BOR design also known as the HL-20 would be a good design for a manned space vehicle. Unfortunately the writer did not know that the X-38 /X-24A design under the PRIME program also went into space on 3 flights, and all were sucess. NASA went with the X-38 since it was known to fly effectivvely. the HL-20 hased a L/D ratio below 3.5 to 1, the X-24A was nearly 4 to 1.
If you stop in at Hobbyspcae.com which is a very good website, you get a real feel for the going on in the alternate space market. Many times they report interesting details. In this situation I recommend the reders read my book "The Next Shuttle" via RocketEngineer.bravewhost.com to get the whole picture of the RLV design concerns.