Fusion, I can't speak to Rio Grande for I've never grown it but I can speak to Heidi since as you know I introduved it.
You say determinate, I waffle and say semi-determinate, as I did in my book. And I couldn't be happier that so many folks are finding out about this excellent variety from Cameroon.
Now it's about Borgo Cellano. I know you like it. I don't.
Chuck Wyatt was the first to list it and he sent me seeds and I grew it, just the once I admit. It had an earthy taste that just wasn't to my liking, but each person has to decide for themselves whether or not they like it.
Furthermore, I don't like the history that Chuck got with it and also listed re it being a variety that was 400 years old.