I would say you were pretty lucky to have an airline send you a check. My general understanding is that airlines will rarely provide cash compensation for expenses incurred due to delays/cancellations even when it is there fault unless it is mandated by law (EC 261/2004). My limited personal experience in asking for a reimbursement involved being given a hotel voucher by DL for a hotel that was full and ending up booking my own hotel. Was turned down for reimbursement and given a $200 voucher instead (the hotel was less than that by a decent amount, and didn't care enough to escalate it). The CoC's are pretty clear about disclaiming liability in these cases --
"We'll do our best to ensure delayed passengers are as comfortable as possible. Gate agents are asked to look after customers with special needs including unaccompanied minors, customers with disabilities and the elderly.
In the event of long delays on the plane, we'll make every reasonable effort to ensure you have food (such as crackers or biscuits), water, access to the restroom and basic medical assistance if needed.
We are not responsible for any special, incidental or consequential damages if we're unable to meet this commitment."