I think this is a well done and very digestible analysis of the difference between forms of creatine. Kre-Alkalyn is discussed starting around the bottom of page 17. It’s a perfect example of how studies funded by the producer can come up with vastly different results than independent studies.
The whole thing is worth scanning through if you have time. My biggest takeaway is that solubility and benefits are closely linked. Makes sense why anecdotally people prefer micronized over non-micronized monohydrate. It also explains why people can have digestive issues when taking creatine. It won’t dissolve substantially in the stomach, and it doesn’t dissolve well in cold water, so if you drink water with creatine suspended in it, it’ll just settle as powder in your stomach and intestines and cause the cramping and diarrhea that people complain about.
It’s hard to justify any form of creatine having more efftiveness, and certainly no better value, than micronized creatine monohydrate.