The only downside I've noticed (2013 13") is that my battery drops somewhat considerably in health when I put heavy stress on the machine. While it usually fluctuates around 96-100% capacity during normal use/charge cycles, putting heavy load on it (such as gaming) has repeatedly and reliably put it to around 90% capacity. I am nursing it back up right now. It is not an exact science at all and I make no claim that this is always the case (or even important). It's just something I noticed about my machine.