We both absolutely hated dummies and were adamant we wouldn't be using one.. until we got a refluxy baby and it was an absolute lifesaver! Totally changed my opinion of them .
DS is 3 and still has his for night time only - although we are in discussions about the 'dummy fairy' coming soon! We have always been pretty strict on when he has it, only for bed or if sick etc. I think as long as you set the 'rules' with it, such as if you'd like to get rid of it at a certain age, and not being a toddler that can't be understood due to having a dummy in it's mouth etc, then its fine. Especially if it's allowing you to get some sleep!