As Asser said, this area offers some of the best diving in the Red Sea.
The Brothers, Daedalous, Rocky Island, Zabargad, Elphinstone all offer excellent wall diving, sometimes strong currents, the odd wreck, superb soft corals, large shoals of fish, all the usual reef suspects, many species of shark (silky, scalloped hammerhead, silvertip, grey reef, oceanic whitetip, occasionally tigers and whalesharks), the odd manta, turtles, etc, etc. I have done several liveaboards out around this area and it really has to be seen to be believed.
St Johns is still a nice spot, with the odd nice wall, but otherwise tends to be coral gardens, etc. Pretty, but not as in-your-face as the above.
However, come in June and you've got to hit Ras Mohammed on the tip of the Sinai. I don't care what anyone says, when that place is 'running' with the breeding fish and subsequent predator pelagics, I think it can compare with anywhere on earth.
Mark