Have not done this particular itinerary, but have cruised with a stop in Alexandria, Egypt.
#1 - on the cruise I did (Millennium), some passengers decided to hire (pre-arranged) private tours to go to Cairo. They ended up with an english speaking guide that did not accompany them back to the ship in Alexandria and the driver DID NOT speak english. A traffic jam and they near missed the ship. But, they saved $30 per person (NOT WORTH IT).
#2 - I'd say a tour from Alexandria to the pyramids, sphinx and the Eqyptian mueseum, like the tour we did. Got to see the things we'd always heard about, tickets to the King Tut exhibit (amazing) we were taken in thru separate doors. Also had dinner on the Nile plus som shopping time. They did everything to ensure our safety, armed guards on the busses and they kept people grouped. Very assuring and a most memorable stop.