I agree. Compatibility isn't so much the issue as much as heads actually surviving the swap / first power on. I've had a few where as many times as I replaced the heads it would ID one time, work for a couple minutes, then go right back to the click of death. Seems the heads are just uber delicate ( which may explain the high failure rates as well).
Though there do seem to be more cases popping up now with media cache and other firmware issues. So perhaps as they are aging more are failing gracefully instead of catastrophically.
Who knows, a few years from now these may be the cash cows that feed us all.