For me the pros have kind of dwindled with each iteration of IOS. But I will list mine for you (these are only my personal experiences)
The ability to apply new themes and keep the experience fresh and interesting
The ability to place apps wherever I choose on the screen
Quick compose and quick reply for text messaging
Added a weather widget to my home screen that shows up-to-date information
Now have the ability to lock certain apps/folders either by passcode or TouchID
f.lux gives a much, much more eye appeasing screen tone in the evening which saves on the eyes
I have customized the colors of my text message bubbles, tweaked control and notification centers, etc.
Tether for 'free' after you consider the one-time cost of the app
Tendency to have to respring or the occasional crash
Cannot simply update to the newest IOS release
Many things I use or install cost $, some a hefty cost especially if you get addicted to customizing and theming
I have a lot of space being taken up by presumably corrupt files due to jailbreaking (14GB)
For me, jailbreaking is a no brainer. The cons are not consistent in that I can go days or weeks without a crash or need to respiring. The Pros are there every time I fire up my phone. Nothing appears to be coming in IOS 7.1 from what I can see that would cause me to give up my jailbreak. Maybe IOS 8? But even then I doubt it. But when I get the next iPhone in Sept or whenever it is released I will be forced to give up my JB and i will go through my annual adjustment period / withdrawals lol.