[240 2NR]

Well Viscous is a type of lsd.

Other types are clutch and mechanical.

Viscous operates like an open diff until enough wheelspin is created on one wheel to heat up a fluid tothe point where it become viscous enough to transfer some of the power to the other wheel.  This is the best bet for a daily driver as it should be unoticable in regular driving and only apparent under heavy load/low grip situations and will probably work best in snow.  it's also the cheapest

Mechanical and clutch type both start with a 50/50 split.

A clutch type uses clutches with a varying number of discs to determine breakway torque.  Problem is a high breakaway that's good for keeping traction with lots of power on say a drag strip, will be hard to tolerate on the street and really challenging to parallel park as both wheels cannot turn at the same rate unless one is able to slip either at the diff or against the street surface.  It's basically an on off diff.  It will also be noisy and 2-3 times more money that the stock vlsd.  example is KAAZ

A mechanical is torque distributing.  The mechanics of it I do not fully understand but these are suppsed to be the best and are relatively unoticable to the driver.  This is your (also the sytem employed by audi) quaife unit which will be as much or more than the clutch type and will be worth it for serious racing, though probably not worth the money as a street jobber.  It also require some resitance to slip for mthe road surface so it will function like an open diff on some snow and ice from what I understand.

A dirt track racer will use a gold box (IIRC) which is effectively a welded diff when on the gas and an open diff when you get off.  I don't know of any applications for the 240 as it's primarily a circle track only deal, but they are pretty darn cool and would make a great drift application as that's what they are essentially designed for.

Streetable- vlsd or mechanical
racing- clutch, mechanical, or welded
for cheap- vlsd