Some comments I have read throughout the internet, tweets, etc, suggest that he was too slow to react and that they had over half the kids out already etc.

Reminder that he started this when they were expecting them to be stuck there possibly MONTHS. The rescue in action now was executed quite quickly and surprisingly (to me), as they had said it could be a long term ordeal. The sub too, was designed it to fit in the narrowest parts of the tunnel as well.

I think it's admirable he quickly got this put together and tested, and flew it over to them as fast as he could.

Likewise, he was respectful and didn't take too much of their time or resources when visiting.

I think he tried to do the right thing. He gave them an option that they didn't have previously. If it's not used, so be it. If they had no other options, then they would have another.