If you have a Recovery Partition that holds an image of your system the way it came from the system, it is always good. You may not be able to use it in the current configuration to restore directly, but an image is an image and can be manipulated other ways.
If you were to have a System Image Backup, you might feel OK about removing the partition, but I would still copy that image somewhere to keep it safe. Especially in the case of not having some other way to recover a system back to a usable state. Even doing that, you may need the 8.0 recovery media to recover an 8.0 image since the 8.1 media might give you a version error and refuse to re-image your system. OEM systems can be very confusing as to their recovery options, but...