When comparing both theories of Kant and Mill, taking into consideration the amount of troubling problems, clearly Mill for me would be a better fit. A decent arguement to support this would be, that Mill has come to a conclusion when speaking of what is morally right and wrong. The Utiltarian would want overall happines. So even if Mill was not happy, but overall happiness was present regardless of the way he felt, then that would be whats best for all.
Kant on the other hand, seems to be a little more less guiding. He wants us to cultivate our talents & have self love. Only when self love is achieved he tells us how we somehow are going against something morally. For example if we are a good liar we are suppose to improve those talents and practice at them, simply because it is almost a sin not to. However, lying is not honorable, therefore making u someone lesser morally. Kant explains the categorical imperative and tells us how we should be able to act only as such when you can will your maxim into universal law. If you cannot then you are not suppose to act that way period. It all can be a bit confusing.