I recently moved to a SW company that does this every 6 months. I haven't been through the review process yet but it seems all consuming for 3 out of the 6 months. My manager has a team of 7 and it seems like he spends half his time on this.
Since I work on HW my projects are long-term and they don't fit this review cycle very well. I also think it causes people to do a lot of nonsense stuff as they desperately try to "make an impact" during the review period. A lot of stuff is done that is a distraction in the name of making an impact.
I get the need to measure people and provide feedback but this constant review shit is ridiculous. In my experience it's clear who is pulling their weight and who isn't.