The manual calls for FXE24HR11, but are there better/alternate options? I want to go with Iridium per the book, do any of you have experience with Autolite or SKP? Other brands?

NGK's also work well in pretty much anything Nissan. In general, NGK electrodes erode less and will last longer, Denso electrodes spark hotter and are more resistant to flooding but erode quicker. Most people choose based on how big a PITA their plugs are to reach. Our QR Altimas are easy so I run Densos in both, but if either one was a V6 I'd definitely opt for NGK's.

I'd just stay with the Denso plugs. Changing to another brand/type may save a couple bux but I've seen some people report issues afterward and have to go back to the factory Denso plug to resolve. I've not replaced the plugs in my '14 Q50 yet (75k miles) but when I replaced the same plugs in my '08 G37s at 78k miles they were still in excellent condition after beating the snot out of it over the years. I did not notice any improvements to MPG nor performance after changing the plugs.