I've been to both for year 12 chem (accelerated at ace and then went to peak in year 12). Both are solid for chem in terms of resources and teaching, you get plenty of practice questions from both and the tutors I had really knew their content well (the tutors I had from both peak and ace state ranked chem). I'd say if you had to pick one, it's worth trying peak out first since they're a lot cheaper than ace and they definitely provide enough for students to be able to do well
