This is a question that’s tricky to answer without just going into another complaint about the New 52 and how it should have been an Ultimate Marvel-esque line instead of a reboot for the entire universe. As much as I enjoyed Gail Simone’s 2011 run with Babs, I hate that it had to be either that book or this one, when I’d prefer to have both.
As it stands now, though, I think it’s probably best to keep Stephanie as Spoiler in current continuity. Her promotion to Batgirl was as much a mea culpa for her inexplicable fate in another story as it was a natural development for the character. Furthermore, many of her traits here were incorporated into “Batgirl of Burnside” Babs, so Steph Batgirl would be redundant today.