When my wife and I visited the Pyramids and Sphinx it was just after the Revolution and the site was fairly empty of tourists, which was tough on the locals but advantageous for us. As expected, what you see is quite awesome when you realise when they were built and the tools they had. We didn't venture inside the pyramids, too claustrophobic and too old for the climb!, but had a really good look around the site.
Our guide was excellent and everything went very smoothly.
If you visit Cairo it's a must to take in this tour and I would recommend it to anyone. Not too much hassle from local vendors selling their wares though they are always around.