We do not recommend running 8080 code.
Why did you go with 8090x Code?
Did you go with 8090 to use Smart Zone to monitor the ICXs? If so that would be a good reason to go with 8090x. I would recommend 8090d. This is the latest code. If not then you can stick with latest 8070 code.
When you change code from router to switch and vice versa, you will need to fix the ip configuration part of it.
Also there are corner cases for upgrading from pre 8090 so please check documentation about it. If you are doing stack upgrades using manifest files you have to follow this corrected procedure:
To upgrade a stack from 8030x to 8090x using Manifest method , follow the below series of steps :
1.Copy 8080e Non-UFIimage Manifest file on the system running 8030x ,Moving to 8080e is mandatory and recommended per Engineering .
copy tftp system-manifest x.x.x.x FI08080e_Manifest.txt all-images-primary
2. Reboot the Stack and make sure all the unit in stack has the image that is upgraded with .
3.Next , copy 8090x UFI image on the system running 8080e
copy tftp flash x.x.x.x SPR08090bufi.bin primary
4.Reboot the stack
5.Copy 8090xUFI image in secondary flash.
Interim step to move to 8080e is Mandatory per recommendation from Engineering.
These steps are not required on a standalone system.
Hope this helps.