I ordered my set of gear diffs today.
They are not the ones mentioned in this thread, they are custom made by a Finnish company. Unlike the ones mentioned here, these should be rather bomb proof instead of plastic. The casing is aluminium and the gears are from a Xray nitro touring car, outdrives are custom machined Tamiya oneway outdrives, should hold up rather well
They should arrive this week, but I will not have the time to install them before next week... Should be quite a bit different to drive than my current setup with oneway on the front and ball diff on the rear