I guess the most important distinction is that SE Jakes writes LGBTQ romance exclusively—m/m romance, to be exact. SEJ writes romantic suspense and contemporary romances.
Stephanie Tyler writes all kinds of romance—romantic suspense, paranormal romance, new adult romance, contemporary romance—all m/f romance with an occasional m/m subplot.
Sydney Croft writes paranormal erotic romance. We’ve called it, “X-men meets erotica.’ And Sydney’s main characters in each of her books is a m/f romance, but there’s a m/m subplot that runs through the entire series.
So there you have it—if you’re looking for m/m romance exclusively, hit up SE Jakes. Mainly into m/f romance, especially with MCs and Navy SEALs? Tyler’s your girl. And if you like a heavily erotic story with a lot of plot and all kinds of relationships? Head for Sydney. I like to say that I don’t change my storytelling or voice for each pen-name—the characters do that for me in each book I write.