For the first time using an animated presentation, the effect can be good. But gets stale over time. More importantly, many a time, we forget the sequence and also forget the point as which transition happens to the next. Thus, we end up pressing a space bar, taking us to the next slide, before we have finished and we have to come back hastily.
Having experienced it personally after creating slides with animations (and as a consequence, stopped using animations), it was quite funny to see the presenter beat a quick retreat to the previous slide during a recently conducted TOGAF training that I attended.