The effects of cluster sets depend quite a lot on (1) the rep range, and (2) whether you are training to failure in each cluster or not. If using a moderate rep range and training to failure (i.e. rest-pause training) then the muscle damage response can be quite high. In contrast, if using heavy reps and training with a couple of reps in reserve on each cluster, then it is possible to get a lot of stimulating reps without much muscle damage at all.