Is it safe to disable System Integrity Protection?

Solution 1:

If you disable SIP you'll get the same level of protection as you had with OS X versions before El Capitan. Whether this is enough for your needs it something only you can decide.

OTOH it's not that much trouble to disable SIP briefly to chance a protected part of the system. If you want to be on the safe side, disconnect from any networks while you do this.

Solution 2:

I felt like it had a negative impact on the battery life of my macbook pro(around 300 cycle counts but not more than 300).After I disabled SIP, I was hardly getting five hours of battery. Few days ago, I enabled it, and it's back to normal.

About the safety issue of the core system file :If you know what you're doing, you should be fine. The following link should help you more about the SIP. http://www.imore.com/el-capitan-system-integrity-protection-helps-keep-malware-away