There is always a lot of talk about having to replace these two components on SE guitars, and I have to say I kind of disagree.
When I finished my Gucci-Top I had a set of Grover's and a set of locking Gotoh's that I could have put on it, but I didn't really find the need to. I frickin' hate the locking mechanism on the Gotoh's and since this was a non-trem guitar I didn't feel like I really needed them, I had lived with the SE tuners for a couple of weeks and had no trouble staying in tune. I have had three sets of SE tuners and I even used a set on a budget 335 I had, as long as everything is snug they work well.
SE nuts are cut for nine gauge strings, I'm not sure what they are made from or how the material is different from the two I have on my US CE's, but after widening the slots for tens on my Orianthi SE I can still dive-bomb and warble while remaining as perfectly in tune as an electric guitar can be.
I will admit that if you are using one of the trem equipped SE guitars and you want to do wide-travel dive-bombs you absolutely must swap out for locking tuners, but I think a new nut may not be entirely necessary, if you are a little handy.
I just wanted to "put it out there" that I have had some really positive experiences with these components, without feeling the need to change them, with a little love and attention to them.