Absolutely! My Air and 5s reboot 5+ times per day. It's so frustrating, especially when I'm with a client. The jailbreak isn't worth actual functionality of the OS.
But that's not a fault of the Jailbreak, tweaks or app which are related to jailbreak.
You're responsible for what you install and you have to check if every single tweak/app is compatible with your device and compatible with all other tweaks/apps you have on your device. So don't blame Jailbreak, tweaks or apps to make your system unstable.
If you just install safe and compatible tweaks/apps from trustworthy sources, then you shouldn't have any problems after all.
I hope this message isn't too offensive, it's not a "attack" on you (if it seems so, then I'm really sorry^^), it's more a statement to all who blame Jailbreak and everything which is related to it if something bad happens with their devices.
Not a chance. At this point, none of the tweaks that I value from jailbreaking are set to be implemented in stock 7.1. My jailbreak experience is smooth, the tweaks improve on my efficiency and satisfaction with the device, etc. I won't give up my jailbreak until forced to when I purchase the next iphone that will almost indefinitely come pre-loaded with the next generation of IOS.