I dove Bikini and Truk in July and wouldn't hesitate to go back. Yes, I have done more challenging dives, but considering the wrecks you have to view and the relatively limited time you have to view them (6 days, 2 dives a day), there is plenty to see from the outside without penetrating. We dove in a group of 4 and a second group of 5, no one had to wait for anyone else, other than the photographers and video people (like myself) who tend to linger. They do have a rigid schedule, but until they are going to require a minimum cert of extended range, there is really no choice given the remoteness of the location.
If I were fortunate enough to go back, I would try to do it with all technical divers, with all the proper training to do some more challenging dives/penetration. These wrecks are awesome.