Yes, as a firmer mattress, this model would generally be a better match for a back or stomach sleeper -- with some exceptions.

The biggest possible exception is if you or your partner are plus-sized (eg, over 250 lbs), in which case this model will not feel as firm for you as it does for others, and thus might actually conform sufficiently to your curves to provide sufficient pressure relief and proper spinal alignment.

Another possible exception is if the sleeper is a young child, in which case they are very light and their body does not have many curves in the first place, so the minimal amount of cushioning provided in this mattress would likely provide adequate pressure relief and would conform sufficiently to their body to support their spine in a neutral position while sleeping on their side.

If you are unsure, the best thing to do is take our mattress match quiz: https://www.goodbed.com/mattress-finder/quiz/?recent=mattress,serta-perfect-sleeper-danebury-firm

If you take the quiz starting with that link, it will give you a match score for this particular model based on all of the relevant considerations (for either you alone or you and your partner together), and will also show you the best available matches for you (both online and in your local area).