It will certainly help with the chaos that is there at the beginning of the swim and I agree re easier for lifeguards. I guess they will have to adjust the 2:20 cut off as well to make it staggered based on when you start so the people in the last group get same time as people at front. Also, they need to make sure they group people based on where they expect to finish the swim. I can see it now, someone who is even slower than I am saying they will be done in an hour - like a swimning speed bump

See here is where I don't see how the logistics are going to work. From what I've read, nothing official, it won't be like the corral systems in marathons, it will be first come first serve. So since they aren't going to extend the 17 hour deadline, which is fine because it's 15 or 16 in Europe, then you'll have slower swimmers clamoring for the first "wave" spots so they don't get cheated on their 17 hours. Then yes they'll be road bumps. Also what effect does this really have in places like CdA or IMFL where it's 2 loops? Again I think the premise is solid, just not sure about the reality.

IM Louisville is already a TT start and is a first come first serve. The swim cutoff is at 2:20 after the last swimmer enters the water. The end time is still 17 hours (Midnight) from the gun. So if you are first in the water but just make the swim cutoff, you have less time to make the bike and run cutoffs. Good, bad, or indifferent that is how it is done at IM Lousiville.

I realize that. I also know quite a few athletes who don't do that race because of the TT start.

I'm not sure how a TT start would factor into the decision to not race Louisville. The process is very easy. You get into the water much quicker than with wave starts that are typical with HIMs.

there are lots of folks who feel the mass start is an essential part of the IM experience. I haven't done one so I really don't have much of an opinion. Personally I don't care. If they send you out 100 at a time I can find someone's feet to sit on.