Hi mate, being modern from an investment point of view they are basically worthless anyway, if you kept them carded for the next 20 years they might increase in value maybe a dollar or two, they would probably still be worth less than what you paid for them.
Id do what ever makes you happy, i totally understand you not wanting them to take up space, i personally think if you want to take them off the cards, do it, have fun, save space, obviously taking them off the cards they will be worth even less than they are now, but its no huge loss, we are only talking about a very small amount of money.
cheers