It would be nice if they did some real work for a change and updated modifications this decade.

For example the parts in the differential that have to do with gearing are not the same parts that affect whether or not it is limited slip. For the average car person you are usually limited to a few factory ring/pinion options either from different option packages OR if you're lucky you have a car from a manufacturer who was building from a parts bin and you have like 8 gearing options(90's Nissans). Then if you are rich you can buy a quick change rear end and do whatever the hell you want by changing the sizes of 2 different gears. LSD options are also a hell of a lot more complex than just 1, 1.5, and 2-way. On the extreme end there is welding or using a spool(attached both axles together), either of those 2 options is hard on tires, axles and in many situations handling. Then if you don't mind mechanical noise and/or maintenance there are a few mechanical locking options with varying levels of aggression. Then on the soft end of things there are viscous limited slip differentials and helical(mechanical torque biasing)differentials. Regardless of the style of LSD they all make very noticeable driving differences and change the on and offroad abilities of a vehicle much more than people give them credit for. Also, of course, open differentials(which manufacturers often put in their lesser-optioned sports or offroad models to make them feel much less capable and sometimes for example in the case of BMW they weld them to the ring instead of bolting them so if you buy say a 135i instead of a 1M you'd have to buy an entire differential assembly to get rid of the 1-legger).