The etiquette on how quickly to return texts and other messages depends more upon who sent it more than when it was sent.
What I find disheartening is how we've come to accept that our texts, emails, and phone calls don't warrant an immediate response, or worse, any response at all. Though it's become the preferred method, I'll never understand why the "no reply" has replaced the "No, Thank You." In truth, it has less to do with gender roles and more about involvement levels. The more connected we are when we're together with the message sender, in general, the faster we respond when we're apart.