This wouldn't be a good choice if you opt out to converting your XZT back to BTC since Coinbase is known to underprice their rates considerably compared to it's current fair market value. If you would like to maximize the money you invested in XZT looking for a direct buyer for it should be the best approach so you can avoid fees and commissions from exchanges for their withdrawal method. Looking for a direct buyer wouldn't be that hard here in the currency exchange section just use a trusted escrow if you would be trading it to a untrusted member.