I worked for a global firm that provided certain HR services to other megacorps, but I have to say that for the most part, our internal HR was abysmal. For example, when I was transferred overseas, I demanded several conditions that were important to our family. However, when it came time to live up to those conditions, HR decided, for whatever reason, that I didn't need them or deserve them. We went back and forth, over and over again, until I threatened to put myself and my family on the next plane home...that got their attention. At the time, I was pretty specialized, and was the only person who could do that job in both English and the targeted Asian language. It would have cost them several times as much to hire a consulting firm than to just live up to our agreement.
Second serious instance as an example: in 2009 after being in target country for 8 years longer than originally agreed, I was still irreplaceable. I went to the CEO and told him that I would stay, but that we needed to work out an exit strategy, because I couldn't stay forever. We worked out an agreement for 4 more years, ending at the end of 2012. SR VP of HR was in the room, and we all agreed that a contract would be forthcoming. It didn't come, and didn't come, but thankfully the basics had been outlined in emails going back and forth. Then the CEO was fired...and I waited, and prodded, and waited, and prodded. Eventually, September of 2012 comes around, and I essentially went to the CEO and demanded the agreement in writing. I had a very good relationship with him, for the most part, and we worked well together. HR and legal finally got something to me, but it was missing a lot of things we had agreed, so we went back and forth again and again...thank goodness for those emails documenting the agreement from 2009. But HR still tried to suppress parts of what had been agreed. The way I saw it, HR was unhappy that someone would receive so much as a parting gift, but, it had all been agreed years before, and was largely based on my performance for those last 4 years (and my division had stellar performance compared to my peers' even during the recession. In any case, we signed the agreement just before I called the movers to come back home. I was not about to leave until they came thru with the documentation, and at the end of the day, the CEO was on my side in that respect, and he called them (HR) on their games.
All of that said, I did respect and support the HR dept in my division. At one point, I gave my HR dept head a letter of reprimand, telling him that if he didn't light a fire under his dept, he would be let go. He lit a fire, got things going the way they needed to be (turning the dept into a support team instead of a bureaucracy), and remains one of my best friends to this day.