Agreed on all points here:
* Doesn't work on Firefox (for a better part of a year now for me, which appears to be an intentional won't fix)
* Frequently causes Chrome to hang or crash
* Pretty noticeable resource hog when it does work
* Audio/video quality is absolutely garbage, frequently breaks up or stutters, and has poor frame rate and high latency
* Seems to do a poor job isolating voice from sound (a handful of people will pretty much cause nonstop background noise, it tries to be clever by muting you when it detects mostly background sound, but it just results in people talking without realizing they're muted)
* Pretty feature poor compared to competitors (master presenter, remote control, shared whiteboard, phone dial-in, phone dial-out)
* Tied pretty heavily to a Google account, which is incredibly annoying in a professional environment where people are hesitant to join with their personal account, plus some extra confusion when it auto-joins with the account signed into Chrome which is further aggravated by the poor multi-account management story that might still use your personal account when you have a business account.
Source: used to be a consultant and used every possible conferencing software under the sun; currently using hangouts enterprise for work