Well depends, if you are specific on applications. For casters in steel mills, we have successfully replaced Klueber Stabutherm GH461 with Molykote G-0106 Sitela 1 and with successful results in last 2 years. In Motors we replaced a Klueber grease with Molykote G-0100. Again succesfully running for over a year at a steel mill.
Sometime Klueber has products that we find are over qualified for specific application (or are recommended accordingly!). As a distributor for specialty lubricant offcourse this is an interesting market for us but before a change recommendation, the application area is studied to understand the temperature, environment, speeds, load conditions, etc. A shortlist is made and based on some precedence or experience with a similar application in the past, we have often made recommendation for a changeover either for considerations of getting something more competitive or sometimes better result itself (like a grease for a pump bearing where we, i think gave a relube interval of 1 month versus a klueber relube interval of 21 days).
As i said, these are specific examples I can share from my experience.
BTW: why are looking for the change - availability issues, prices, service ??
I think you could also refer to the machine manufacturer for an alternative suggestion if the machine is under warranty or otherwise. There are over a hundred brands available and most OEms do give atleast 5-6 options for a suggested lubricant brand.