These are LSD style diffs:
CEN:
Ofna:
Kyosho:
This is a standard diff:
Kyosho:
A standard diff has 6 gears and 2 cross pins that allow even diff action and puts power to the tire with the least amount of traction. A Limited slip differential had plates or many gears that lock up the diff as it spins and applies power to the tire with the most traction or more evenly applies power to both wheels.
Cen is working on a standard diff and we are currently testing them.
The Kyosho 7.5 Kania Edition came with LSD diffs. The Ofna Hyper 7 PCR comes with LSD style diffs. The Cen Matrix comes with LSD style diffs too.
With the CEN diffs, the lighter the oil, the better they work. 80wt gear oil works good, as well as grease. When using grease, pack it for a stiffer feel, or lightly coat them for a lighter feel. You can also remove the 2 orange O-rings for an even smoother feel since there is no oil to leak out.