In testing several AIOs, I've seen some that are fairly decent, but other that haven't impressed me, but the real problem is that once someone reads the words 'liquid cooling' they immediately think it performs like full watercooling, and not more like....decent air cooling, or worse.
I've also seen some air coolers that are really impressive that actually surprise you how well they function, and for lower cost.
The thing about cooling is getting down to how well a cooler is designed and the attention paid for thermal deltas and heat exchange, rather than making it look cool first and performance secondary or even tertiary.