If you're undecided, I would suggest going.
Ikeda - Made over and above effort to get his hands on every attendee and work with them. Is doing some great stuff. Very connected body and can take center on contact. Sometimes struggles with language barrier but makes a strong, honest effort to try to explain what he's doing.
Heiny - Wonderful teacher. Very perceptive eye on what you're doing wrong and how to fix it. Very connected body and can take center on contact. Very good at explaining what to do and how to do it. Is doing some great stuff.
Ledyard - Of the three, I have only had a very brief time on the mat with George and it was outside of aikido. But, I will say that he was friendly, dedicated, and hard working. There was no ego, no trappings of rank. He had a genuine smile and a sharp mind. So, while I can't say anything about his aikido because I haven't had the fortune, yet, to experience it ... I can say that if the short time I was able to train with him is any indication of his skills and abilities in the aikido world, I think you'd find yourself in more than capable hands with George -- as an aikidoka, as a teacher, and as a person.
Not a seminar to miss with these three.
It really is a good time in the US for martial arts right now. We have a lot of great teachers out there. It's very much worth getting out and experiencing them.