1.6 to 1.9.2

Alright, I'm finally ready to jump from 1.6. I had been holding off because I was working on some projects that needed to be run off and finalized, and I was paranoid when people were saying some projects had become jumbled or messed up when they jumped from 1.6 to 1.7. Is there any reason to worry about that stuff now or do you guys think it's 100% safe? Had that issue been fixed?

PS I'm running a 2015 macbook pro 10.10.4 OS X Yosemite.

Thanks!

Backup 1.6 in a folder and install 1.9.2
But then im not so sure its a good idea, since you might have to update the firmware for running 1.9.2, and dont know if after updating the firmware if you still can go back to 1.6. Better clear that with someone inside ;/