I'm UNBELIEVABLY frustrated with Lightroom!!!! I have/had a MacBook Pro that was only a couple of months old when I installed Lightroom on it. Very shortly I had random crashes of my OS. The crashes got worse-- seeming to have nothing to do with Lightroom-- the machine would crash whether on battery power or plugged in, whether Lightroom was being used or not, and the problem just got increasingly worse. The geniuses at the Mac store said it seemed to be somehow connected to Lightroom, according to the crash supports. But, my machine got so messed up that they completely replaced the logic board and other parts. I've had it back from repair for two days. Installed Lightroom again. WITHIN FIVE MINUTES OF USING LIGHTROOM AGAIN IT CRASHED MY MACHINE!!!!! RANDOM SHUTDOWN!!!!! Brand new Mac, twice in a row. And, now I have to wonder if it has screwed up my machine again! And, of course, getting a Lightroom tech on the phone to help me seems to be impossible. They make it incredibly hard to contact support. I travel the world for a living, meeting thousands of people a month-- and, I'm going to tell everyone to stay very far away from Lightroom. Couldn't be any more fed up.