We nearly talked ourselves out of it. Read enough about Egypt online and you can convince yourself pretty fast. In the end we just booked it and paid for the version that takes most of the stress away. Private guide, everything pre-arranged.
Best decision we made. Cairo airport is a lot and I genuinely don't know how we would have handled it without someone waiting on the other side of immigration. It's loud, packed, and nobody is in any rush at all.
We stayed at the Four Seasons on the Giza side. Ask for a Pyramid view room if you can. Ours looked across towards the Nile and on a clear morning you could make out the Giza plateau which was a nice way to start the day. The beds are genuinely one of the better nights sleep I've had in a hotel and the breakfast is a proper spread. There's a heated pool on the fourth floor overlooking the Nile and we ended up using it one evening when we got back late and just needed to sit somewhere quiet for an hour.
The GEM needs a full day. The Tutankhamun rooms are as good as you'd expect. The gold mask in person is genuinely something and the number of objects from that one tomb is hard to get your head around. The Grand Staircase is also worth knowing about before you go in. Huge royal statues lining the whole way up through the atrium and it sets the tone before you've even reached the first gallery.
Pyramids we did early, around 7am. Still busy, it's always going to be busy. The scale of them doesn't translate in photos at all. Be prepared for the camel touts at the gate, they are very persistent.
The traffic in Cairo looks completely lawless but our driver explained the honking has a system to it. Short beep means I'm coming through, double beep is a thank you. Once you know that it's a bit easier to be sitting in the middle of it.
Bring cash for tips and bring more than you think you'll need. We weren't prepared for how constant it is on day one and it coloured the whole day. By day two we'd adjusted and everything ran smoothly.
Won't be going back only because there's too much else to see. But absolutely worth doing properly.