The MTEB benchmark was never that great since embeddings are used for more specific domain-specific tasks (e.g. search/clustering) that can't really be represented well in a generalized test, moreso than LLM next-token-prediction benchmarks which aren't great either.

As with all LLM models and their subproducts, the only way to ensure good results is to test yourself, ideally with less subjective, real-world feedback metrics.