You didn’t answer my question: Were there any specific, supported, complaints?
Also, what was methodology of applying correction?
As for everything having drawbacks, sure. Any manual process requires expertise and time to get right - that’s the drawback. Lack either, and results are likely to be suboptimal. Most of the valid complaints about processing come down to lack of user expertise - bad starting measurements, poor gain staging, asking tools to do what they cannot, etc. The rest of the valid complaints tend to be from shortcuts in the measuring or optimization process, or defective/incompatible hardware. Others are audiophool idiocy for the most part: bitching and moaning about non-issues such as sample rates or an extra A/D conversion for example.
But the bottom line is, without modern EQ tools it’s near impossible to get the bass right in a small room. Given that bass is estimated at 30% of preference, the logical inference is that anyone interested in fidelity should learn these tools and use them.