The primary advantage of such a craft is getting from point A to point B very quickly indeed (orbital velocity is Mach 25), but as many people have pointed out the vehicle moving at that velocity is essentially travelling in a straight line. You can manoeuvre, but it will be both costly in energy, time and space.
So the actual function of the vehicle will be as a carrier platform. A target is identified, and the the vehicle is dispatched. Over the target area (or in international airspace, depending on the scenario), UAV's and UCAVs are dispensed, which slow down to operational speeds and then carry out the mission. Alternatively, projectiles resembling darts are released and coast to the targets at @25 times the speed of sound. To put that in a bit of perspective, the jet of molten metal projected by a HEAT charge is also moving at Mach 25, and that few ounces of metal can penetrate heavy armour and destroy a tank or bunker.
While no hypersonic dispensing of weapons or vehicles has been demonstrated yet, it is an extension of dispensing UAV's at high speeds, as demonstrated by F-18 fighters. Without doing too much handwaving, it can be assumed the weapons and UAV's are designed to withstand the ejection at speed, and rapidly orient themselves to the target once clear of the plasma sheath of the carrier vehicle.
Perdix deployment from an F-18
The plasma sheath represents both a cost (the vehicle will be highly visible once in the atmosphere) and an opportunity (the sheath is proof against both radio waves and lasers, providing defence against hacking and a whole class of directed energy weapons).
The final issue is what form factor would work best for such a vehicle? I would suggest a "wave rider", which "surfs" on its own supersonic shockwave, providing a much more efficient use of energy, and can carry the dispensed weapons or UAV's on the top surface, which is largely clear of the effects of hypersonic flight (the shockwaves are trapped beneath the vehicle)
Possible design for a Mach 25 Waverider
So an SSTO craft would serve most effectively as a carrier and dispenser of the actual combat vehicles into the target area.