Jailbreak ios 7.1.2 vs ios 8?

I have an iphone 4s running on sprint 3g. My upgrade is in 3 months, and I was wondering if I should jailbreak or upgrade. Is jailbreaking safe?

IOS 8 is better. You just need to register your device's UDID with a developer account through a site like http://www.udid.in/.