Narrow down your focus and explain your objective
While the two classes are similar, they play differently. It is unclear what you consider to be "more powerful" and that could conflict with my (or the next person's) view of what is "more powerful". While one may be more powerful in one aspect of the game, the other may be more powerful in another.
You could start by describing what are your goals with that character, or how you think that this choice would impact your gameplay, or how that would interact with the group.
As it stands, we cannot possibly answer that question without injecting our own opinion into it (compare your question to this other: Is this question too opinion-based). While I could easily answer that question, because I would have to rely on my opinion about the rules, it may not be exactly the kind of answer you were looking for, and thus we need clarification.
If you asked us "what is an optimal choice for a controller spellcaster" or "what class gives the highest spell DCs" or "what class has the highest damage potential", those would all be fine and not based on opinions.