I have 2 orbital engines behind the shroud, generally used for active descent and adjustments. No jet engines as all fuel usage comes from the propulsion module and the little thrust that the orbitals give me is just to add a little thrust for course correction, so there has been little incentive for me to add efficiency. The landing is usually full-proof anyway as the parachutes will usually "auto-correct" any landing. The launch vehicle I use is essentially a KW version of the Delta IV with some SRB's...it is grossly overpowered. I am amazed at how well I can throw anything at this shuttle as it work so seamlessly with everything else. Really a nice job.