I pretty much agree with all your viewpoints here, Helix in particular is a good ride but I've never found it to be the amazing ride that others do. I too prefer Icon.
I think stacking is just an inherent trait of dive machines, I'm yet to ride one that doesn't stack in some way. I find Balder incredibly repetitive and I don't find the air time that interesting. I think I prefer the out of control woodies like Wodan and Wicker Man too the more controlled way Balder rides.