I have only one experience to share. Interviewers (2) asked me to choose my favorite time to be phone-interviewed in a window of 4 hours, 9-13, more like 9-12.30 because by 13 call had to be completed.

I took 1 hour off from work to attend, then the "conf room" wasn't working (conferencing pin code was wrong). This made them re-schedule the call. Then they asked me to re-schedule again. Then again.

Finally we arranged for a given time and day, with a working conf room. When I called-in they were interviewing another developer on the same conference room. And it wasn't the previous interview... they actually scheduled two interviews at same time because they messed up with time zones.

They canceled or rescheduled interviews giving note no more than 30 minutes before the agreed time. So in all this I lost 4 hours of work. At the end I gave up and withdraw my application, not worth it.