Is this Serta really firm, or does it feel softer than expected?

It is genuinely firm at 8 out of 10, though a few owners note it reads a touch softer than a true firm bed and slightly firmer than expected in the first couple of weeks as it breaks in. The two inches of gel comfort foam add a balanced cradle rather than a stiff, hard surface, so the feel is supportive with a little give. Give it two to three weeks to settle before judging the firmness.