No offence, but given that every single TC avaliable on the market comes with a rear ball diff, that should answer your question on that.

A oneway gives a much higher level of steering into a corner than a spool does. The front wheels are allowed to freewheel, which means they can give a greater proportion of their avaliable grip to cornering forces, rather than traction. However you do loose front braking, effectively meaning you apply a handbrake when braking with a one-way (not good).
Usually, the fastest lap times will come with a one-way, however they can be hard to race other cars with, as there is normally only one line you can run. They are good for indoor when running rubbers, and large high speed outdoor tracks.

A spool works by locking the two axles together. This takes away some turn-in, but gives loads of mid-corner to exit, on-power steering. effectively the front of the car pulls the rest of the car out of the turn. And you still have braking ability, and it is much easier to turn consistent laps and race other drivers with a spool. Mainly used outdoors on asphalt, with rubbers.

A front diff is kind of the middle ground between the two. With foams indoors, or very tight and twisty indoor rubber tracks.

Hope that helps.
Ed