Turn off iMessage on your iPhone so you will get your texts from iPhone people. If you have iMessage on any other devices (such as an iPad or Mac) go into the settings of each one and disable your phone number. If they are still logged in then text will still go to those devices instead of your phone.
Go to settings, then about phone, and repeatably tap on Build number until developer options becomes available. Then go to developer options and change runtime from Dalvik to ART. Makes the phone run just as smooth and fast as the iPhone.
Go to settings, then about phone, and check for any software updates. It should be up to date.
Download evolve SMS if you don't like hangouts, its free and has no adds, but it has some extended features you can purchase if you like it.
Setup a Google voice account to get your voice mails. Then download the Google voice app and after you have logged in go into Google voice settings and set "View and display voice mails in call log" to on. This way you can see all your voice mails in the phone app just like on the iPhone.
Download NiLs and NiLs Floating panel from the app store. This will show your notifications on your lock screen and allow you too open right into them or even take actions (such as deleting an email) right from your lock screen.
If you listen to podcasts, get pocketcasts. It is a great podcasting app and is cross platform, so if you do go back to your iPhone you can download the app there and keep all your podcasts in sync across devices. They also have an iPad app.
Get isync if you want to continue syncing with iTunes. You'll also have to download a companion app to your computer, but after its set up you can sync over WiFi or USB with iTunes.
You can also open a Google Music account and import your iTunes library there, it'll just take a while depending on how many songs will have to be uploaded to Google.
You can also sync your iCloud mail and contacts. Check this guide:
http://android.appstorm.net/how-to/...-sync-part1-data-email-contacts-and-calendar/
If you don't want to do that, you can import your contacts into gmail by logging into your iCloud account at iCloud.com, then go to contacts, select all, then export. Once the file has been exported go to gmail, contacts, then import and select that file and everything will be ported in. These step are to be done on your PC browser.
If your syncing your favorites with your desktop and are not using chrome, download chrome and import your favorites from your current browser into chrome. Then log into your account from the chrome browser on your nexus and they will be imported automatically to your phone.
Enjoy your phone, then Nexus is probably the best overall android phone out, though the Moto X is very close and has some great features. The software on these two phones are light years better than what the other OEMs are using with the exception of Sense on HTC which is still pretty good.
and Soon to arrive Stock Android..good riddance with all that touchwiz nonsense and the stutter...