BB Z10 is a really great phone. I usally use data on it a lot--- browsing websites every day, texting a lot, watching youtube and playing games sometime. Honestly, if I unplug my phone early morning and the battery may left 1/3 in the afternoon.
Sooo…the only downside for me is heavy battery drain! Because of my usage, extra batteries became my must have accessories…I take these batteries from great manufactories like MPJ around if I am away from a charger in airport, shooping mall or just on the go. Only a few extra bucks bring a lot extra juice, so why not? But I haven’t used those bulky stuff need an extra cases yet, it probably a bit heavier for me.