Installing apps

Hi everybody, I'm waiting for my new Note to arrive, and since it's my first Onyx reader (I currently read on a Kindle Paperwhite) I have a question: is it preferable to install apps from the Play Store (like Kindle and Pocket) or to sideload them directly on the device? How can I sideload them? Simply by copying the apk files on the device?

Thanks for your help, I really hope this device is worth the money :2thumbsup