I think it also depends on how you hobby - if it's something more involved like SA, a separate iPhone burner is best, if there's a plausible excuse. I bought mine used for $150 and used a pre-paid $30 Tmo 5gb/mo plan that I could refill with top-up cards bought in cash.
Girls instinctively trust iMessage users more, and you can also use iMessage on other Apple devices, which gives you some flexibility and additional responsiveness. You can set up something similar with an Android burner and using Google Voice across platforms, but true amateur SA girls seem to like the "validity" of those blue iMessage bubbles. Either way, I like having a set up that allows me to communicate via desktop because I'm often in front of a computer anyway, and many of my SB conversations cover similar territory, so I can copy/paste with some personalization very quickly across multiple conversations.
If you're seeing pros, an obvious burner app probably doesn't matter. But many non-pros will be put slightly on-guard by the signature that many of those apps put in each sent text. I don't know if that's specifically true about textra, but it was for text4free and a couple others I tried.