I went to Port El Kantaoui last year on a cheapo last minute half board week with the OH. Hotel was fine, food OK not amazing. The Port is very touristy. I don't know what it'd be like if you're taking the kids, guess it depends on the facilities at the hotel.
Was supposed to be a chill out holiday but I'm not very good at those so we ended up seeing a number of the Roman ruins…. El Djem is cool, Carthage not much to see, but if you can make it out that way try and get to Thuburbo Majus and Dougga – way less sanitised than the more popular sites.
You do get hassled to buy stuff, but I've been to Egypt and I don't think it's as bad as there!