Deleting the record will delete all history of the device. So, you would lose any user history, any management history (i.e. Lock Code, if you sent a lock command.) and data. If you are just re-enrolling the computer, that is probably fine.
If you just select the re-enrollment options, you can choose what data you want to keep after a re-enrollment. For example, you probably want to clear any policies so that any "once per computer" policies run again, however, maybe you want to keep the user history so that you can go back and look who the computer belonged to.
It really comes down to preferences.
