Besides it not having TouchWiz, and it getting quicker updates, what is the other benefit of Pure Android? Does it still need to be rooted for additional functionality? What can you do with custom ROMs?
Thanks.
For me at least here are some benefits.
The notification panel is usually much cleaner. I can add toggles myself (no root required) and/or use the quick settings. I hate having a notification panel that is half full before you ever get any notifications.
There is no bloatware installed. No free trials that nag you. No popups that show up over and over asking you to try this feature. Even the Verizon moto x had nagging notifications that were annoying.
Tethering has usually been much simpler on nexus devices and for a while it meant free tethering (not always the case any longer). It is still nice to have it built in at the system level rather than being an app you need to access (on T-Mobile).
Due to speedy updates your device is likely to be more secure from security threats/malware than 99% of android.
Even though nexus devices don't sell well, because they are reference phones for developers you are almost guaranteed that your phone will be supported by an app and in a lot of cases your phone will be the best supported because the developer uses a nexus too.
And finally there are still a few stock apps that aren't on the play store (from google). I happen to really like the stock clock app because it makes very good use of active notifications.
I'm sure there are more benefits with rooting and romming but I don't do that anymore and I still prefer nexus.