Don't missunderstand what 'surfacing as a group' means when diving with Aldora and how it effects your dive. There are two other factors that will effect your dive bottom time positively with Aldora, first is the DM has a long hooka for the first diver low on air which extends everyone's dive, secondly because they are so successful and busy they are able to separate divers to different boats based on experience and ability. So if you're good with your air, you're almost certainly going to end up on a boat with similar divers. You might be shocked to find yourself actually first low on air, as they seem to attract some excellent divers. Safety is paramount with them, and surfacing together is part of their safety plan, especially on advanced dives, the two other factors I mentioned eliminate any downside to this safety rule. I've enjoyed many 90 minute dives with them. Their divemasters absolutely love diving and they focus specifically on maximizing bottom times. More than once during the dive briefing I've experienced divemasters specifically talking about how they wanted to dive the site with extending the bottom time to the max as one of the major goals based on the profile, and they certainly succeed in this.