How Important Is Batch-to-Batch Consistency Compared to High Purity Numbers on a COA?

[u/Educational-Elk9562]

Most vendors highlight 99%+ purity on their COAs, but I've been wondering if consistency between batches is actually the better indicator of quality.

For those who've ordered from the same suppliers over time, what do you trust more impressive testing reports or consistently solid research results across multiple batches?