Most reviewers use case systems to test in with room ambient as base temp, but do not monitor cooler intake air temp
Room temperature is really worthless. It's the temperature of air going in to cooler that is important, not what the room temperature is.
Their tests results are how well their system is cooling in their room.
I don't have their system or their room.
I could care less how well their system cools.
I want to know how well the cooler being tested cools.
Just changing coolers in a system usually changes the case airflow and therefor cooler intake air temp... Changing cooler fans does too.
You are overstating that effect quiet a bit though i would say. It's just one of many factors that makes cooler testing very tricky and vague in general.