On the subject of 'other space gliders', here are a couple of contenders. Firstly comes the Matchbox Mega Rig series 'shuttle', loosely based on the X-33 concept vehicle, which Matchbox released in a much smaller die cast version, too. Not strictly a glider, it bears a passing resemblance to the classic M2-F1 wedge shape, but is intended as a shuttle replacement. Here I have used it as the passenger section of a custom Nuclear Ferry, way back in 2008.
Next up and more recently, is the Super Jets die cast 'Stealth Fighter'. A much more glider like shape and overall profile, its not really a stealth contender and is clearly inspired by the X series test vehicles.
Finally, an old blog staple, the Hover Space Glider. This particular one isn't my own, but I do have a blue and orange one somewhere in the attic. It was available with a Lunar Rover and a Scramble Bug type toy (visible on the backing card) as well as a saucer like vehicle.
It follows the classic Sword Space Glider design almost perfectly, apart from the omission of the odd 'emergency light' style switch found on most large models.