Moly additized greases are excellent lubricants,however, should only be used in limited applications as the moly can actually cause early failures in most uses. Never, ever use a moly additized grease in a wheel bearing or universal joint application. Moly additized greases are primarily indicated only where extreme pressure sliding action occurs. When Moly is used in non-friction bearings the moly causes accelerated surface degradation (frosted mug appearance) of the rolling surfaces and premature bearing/race failure. The moly is actually harder than the hardened bearing surface and does not crush when the bearing rolls over it. In universal joints, in addition to surface failure, the moly centrifuges to the extremes of the bearing, blocking oil flow, causing accelerated bearing end wear.
If a single grease is being considered a non-moly grease is the safest primary recommendation. The use of both moly/non-moly specific for sliding/bearings application is ideal.
I currently have 5 failed universal joints sitting on my lab table with very low time; all were regularly greased with a moly additized grease and each failed due to the use of the moly grease.
George Morrison