Maybe it's just something with my phone, but I just had a weird problem with this.
Downloaded it to the phone, installed it, restarted the phone, and tested it out. After loading a web page the phone started running extremely slow and then froze all together. Powered off and then the phone would not turn back on again. Thankfully getting into download mode did something to turn the phone on. Uninstalled Nightly, powered off phone, and it will turn back on as normal.