I went to Egypt this year and really had a great time, we did 1 week in Luxor and 1 week in El Gouna (Red Sea) i personally prefered to do a my trips on a coach it is quicker as i did a trip to Dendara Temple and it was the longest day of my life on a boat as they seem to take them longer coming back.
We did Valley of the Kings and Queens and Hampestut Temple (spelling is probably wrong) all was in a half day trip. Karnak and Luxor Temple is another half day. Their is also night cruises and day trips to Temples.
I would prefer on land as i would get bored on a cruise, let me know if you need any tips etc, If you do not have it booked yet i would really recommend the Movenpick hotel as it was really lovely and big with 2 big pools plenty of restaurants and only a few minutes away from all the hustle and bustle and they have a courtesy bus.