There's a lot of discussion in the SSTO field about VTHL vs. HTHL vs. VTVL, and the real issue is wings . A launch vehicle operates in four really different environments: sitting on the ground, flying through the air, falling around an orbit, and plummeting back to Earth at orbital velocity.
When it's in the air, a wingless rocket needs to expend thrust to go up or to descend in a controlled way. A winged vehicle still needs to expend thrust to go up, but not really any more than a rocket would, (perhaps less!) and since it has wings, it doesn't necessarily need to burn fuel just to go somewhere or slow down.
The main objection to having wings on a launch vehicle is that they are just dead weight once you get to orbit. To me this sounds silly, since the whole point of a launch vehicle is to get above the atmosphere and back down again, which means that the important part of the mission is in the atmosphere where the wings are useful. The drag caused by the wings is more than balanced by the lift they produce, which is why aeroplanes have them in the first place! Plus, once the craft is in orbit, the wings have neither drag nor weight! (but they do have mass, admittedly)
One of the tricky things about a reusable vehicle is that it has to get back down from orbit, and by that point it's at orbital speed. Coming back to Earth means it needs to get rid of a lot of velocity. Having wings lets it brake against the atmosphere, like the Space Shuttle. However, the shuttle re-enters so fast that it needs expensive tiles to keep itself from melting. The tiles wear out, and fall off, and are just an amazing headache. This problem could be avoided by having a lower wing loading, which is what the Black Horse will do; it will fly on those wings, rather than falling on them.
To quote someone more knowledgeable:
Reentry heating is a strong function of wing loading. The Space Shuttle has a highly loaded wing, at over 120 lb/ft2. The Black Horse has a 20 lb/ft2 wing loading. Some at Boeing believe it could be possible to build an all metal aircraft (Applying Inconel, Rene 41, etc.) since their in-house RASV design used all metal integrated structure/tankage/TPS. (And handled cryogens, too!).
Any rocket scientists reading this will probably say that these arguments are too simplistic, and they're probably right; I've tried to boil down the argument to the bare bones - but the point is that there are some good reasons for a winged launch vehicle.
. . . back to the layman's view of the Black Horse