I have owned the glass bowl for my stand mixer for about 6 or 7 years.  Not sure what happened with the others whose bowls broke but I have been very happy with mine, perhaps damaged in shipping or user error.  Also, I am not sure how others over-tightened theirs.  It is not required to be super tight, just enough to keep it from moving up and down, the threads will keep it from moving side to side.  The plastic screw base does not need to be tightened too much as it needs to be removed for the dishwasher or microwave.

The amount of light it lets in compared to the stainless steel bowl is nice and I prefer it for most mixing jobs.  Except for whipping cream, etc, since the stainless freezes better.