Hi. Dived both in Hurghada and Marsa Alam. Like both. Enjoyed Marsa Alam more -unlimited (3 a day, really) shore dives, relaxed atmosphere, desert living with no hassling. Got to feel like I met people that were more relaxed and genuine than the tourist hustlers in the big cities that often spoil the overall expression of this wonderful country. There are great liveaboards from Hurghada, but you have to check the weather this time of year. Elphinstone is easyly accessible from Marsa Alam. I really enjoyed staying at the Tondoba eco village.
So if you want some night life etc, Hurghada. If you are into it for the diving, Marsa Alam. best way to dive Egypt is via liveaboard, cheapest is probably Dahab or Marsa Alam, though they say Marsa Alam is in more pristine condition.
The house reef in Tondoba bay is greath with healthy coral, but dont expect any big stuff.
Say high to the goby shrimp and the shrimp goby for me!