I'm not a fan of 3 heats with the top two advancing automatically. With 4 regions there's no way to create "balanced" heats based on place, and times from potentially vastly different competitive situations at each Regional shouldn't be used, either. This becomes stark if/when the top seeds end up not running.
I also don't like the fact that some lanes in the 800 have 3 athletes for an entire lap while other lanes only have two athletes.
When the track has 9 lanes going with 18 athletes isn't much of an issue. It's hard for me to have strong feelings either way. But when the track only has 8 lanes, I am not a fan of the at-large bids. If the meet had never been at JO w/9 lanes, I doubt the at large bids would have ever been approved. In my opinion, the at-large bids should be dependent on whether the championship track will have 8 lanes or 9 lanes; otherwise, let's just go with 6 qualifiers from each region and fill the lanes.