I am not really clear on what you are asking here -- what two positions you wish us to choose between. It looks like you might be asking us to compare between Kant's categorical imperative and deontology. The problem is that the categorical imperative is an example of deontology and so we cannot really compare the two.
Deontology is a school of philosophy that judges our actions based on whether they conform to certain rules of morality. This is as opposed to consequentalist ideas that judge morality based on the impacts of the actions.
Kant's categorical imperative is clearly deontological. It sets out a formula for determining morality (whether we could will that our action be the basis for a universal law) and judges our actions according to that formula.
As far as which position makes most sense to me, I have always thought that the categorical imperative was the best statement of how to judge the morality of an action. But I do not know which other position you wish to compare to it.