How bad would it be to install El Cap then Revert?

[bcam117]

This would all be on my main partition. Don't think I can make a 3rd partition as the last time I did this it broke bootcamp.

 

[Itzamna]

Do a fresh install when reverting and it's like new.

 

[crjackson2134]

Restore from your backup.

 

[iamMacPerson]

This would all be on my main partition. Don't think I can make a 3rd partition as the last time I did this it broke bootcamp.

Use Carbon Copy Cloner or SuperDuper to make a bootable backup of your hard drive before the update. If you wanna go back, just use a thumb drive with Yosemite recovery, then use Disk Utility to wipe your internal drive. Then, use the restore function to put everything back.

I had to do this with the very early betas of Yosemite when things were still broken.

 

[mmomega]

installing it to a virtual machine will save you a ton of time if all you want to do is try it out.