What do you think about the Juniper MX line?

Hello, I've been doing some research into using the MX line of Juniper routers and was interested in hearing people's experiences (the good, bad, and ugly). What do you like about them? What do you dislike? Where are you putting them in your network? Where are you not putting them? Why? What other platforms would you consider and why? I hope to hear some candid responses, but feel free to respond privately if you need to. Thanks!