anything you read about fancy formulas (ether esters, etc.) is mostly marketing. monohydrate is where its at -- creapure is the gold standard here. its licensed and in many different brands.

the effects are not mind-bending and its certainly not like taking exogenous hormones. but! it will improve strength and capacity at the margin for super short duration, high power output activities (eg. lifting, sprinting <100m).

source: have taken creatine almost daily for 15+ years (zero side effects) and coached athletes at the local national, and international level in olympic weightlifting.