It is not just a matter of personal preference. The periphrastic passive ("ser" + past participle) is subject to lots of restrictions of use, whereas the passive reflexive (using "se") has very few restrictions.
As far as I know, there is very little literature on this topic, and the very little that can be found, it is not written for the common people to understand it easily, but written by grammarians for other grammarians to read. The problem is that you need to take into account the aspect of the verb, the tense in which it is used, its interpretation in the sentence, and other factors, so it is a rather complex topic. A few rules that could be useful (if you can understand them).
' The passive with "ser" cannot be with verbs of perception followed by infinitive (e.g. La casa fue vista arder)
' Perfective verbs tend to reject impefective tenses for punctual events (e.g. "La carta es escrita"), and must reach a definite end.
' Imperfective verbs tend to reject perfective tenses (e.g. "El cuadro era pintado"), and they can only be used with generic subjects (e.g.. "Pepe es querido por su madre").
' Intransitive verbs of motion with transitive uses (e.g. andar, subir,...) do not accept the passive with "ser".
This is just the tip of the iceberg. It is a very complex subject, and the bottom line is: the passive with "ser" has lots of restrictions and there are just a small handful of situations where its use is justified, whereas the passive with SE very few restrictions, which is maybe why speakers tend to prefer the passive with SE, and why everything points to the disappearance of the passive with "ser" (although it could survive forever, who knows'). Also, they are not always identical, but this is another story...