I don't mind paying the price of FlexRaid to have everything managed by a single product, intuitive interface, and a good support forum.
Another option I've read about is NZFS, but know nothing about.
Reading through the technologies is confounding, and rather read through features. All I want to know is what a product is going to do for me, and what the other ones will do. I think most of us want features to increase our media storage by using multiple drives, error detection, error recovery, drive pooling, network sharing, easy to manage. If FlexRaid is the top choice, I'll pay what they are asking to save me time and a headache.