It’s a topic with no clear answer and it largely depends on personal preference and how you use your vehicle.
For road cars, a diff is pretty much a must and an LSD is a great option. I have auto torque biasing (or Torsen) ones in a couple of cars and a Detroit locker in another 4WD.
For lightweight, chain drive, off-road, 2WD buggies the decision is less clear. An open diff is not going to work in this scenario as you’ll just be spinning one wheel, so we’re only talking about limited slip or locker units vs no diff here.
LSD vs No Diff
- Reduces understeer for low speed handling on grippy surfaces like asphalt
- Easier to manoeuvre your buggy in the pits or onto the trailer
- If you’re planning to hill climb your buggy or autocross it’s a good option.
- Relatively fragile under shock loads (jumps)
- Wide; they reduce axle length and therefore wheel travel
- Depending on the type you choose they can:
- act as open diffs unless both wheels are on the ground and have some traction (ATB).
- act as locked diff all the time in a light vehicle on loose surfaces (strong clutch type or viscous)
- lock and unlock affecting the handling, especially on variable surfaces (lockers)
- perform differently under acceleration and deceleration
There are some excellent resources on the different types of LSDs and lockers and how they work to increase traction when you need it.
Read something not written by the manufacturers for an unbiased view. There are many ways around the limitations too, unfortunately most increase the cost.
I generally recommend a no diff set up for Rorty buggies, the con’s of the LSD outweigh the pro’s for me.