@BobSassafrass: I've seen vibroswords with mod slots, the commendations vendors on Coruscant/Dromund Kaas sell some, and modded vibroswords are as powerful as modded lightsabers (and use the same components). If you keep replacing the mods you could use it from 16-50.
Not sure about how common they are at 50, though.
Vibroweapons usually have a cortosis weave giving it the capability to block lightsaber blows.
For you n00bs:
Cortosis ore was a very rare, brittle, fibrous material whose conductive properties caused lightsabers to temporarily short out upon contact, although the wielder could solve this problem by turning the blade back on after a couple of seconds. This effect made cortosis a useful material for anti-lightsaber melee weapons, though with repeated strikes, a lightsaber could still cut through it. Cortosis, due to its heat and energy resistant properties, was also resistant to blaster fire. ~ Wookieepedia