Is StoryOrigin still worth the cost? I've considered going back only because I can offer my subscribers more authors to choose from (I do believe there's some interest fatigue when you keep hosting the same giveaway/sales promo). I have yet to run a ProlificWork promo only because there aren't a lot of authors participating there anymore.
I think you'll get a variety of answers to this. For many authors, StoryOrigin's review promos and the newsletter swap features make it more valuable than Bookfunnel. That said, if you are looking to giveaway books in great volume, and can only afford one, BookFunnel is the better option.
I don't really need reviewers, as I've built up my own team over the years. My list is bigger than most of the authors in my genre on StoryOrigin, and the complications of a swapping, make that feature not valuable to me.
I will probably maintain my StoryOrigin subscription at the end of the year because I do think it gives me a chance to reach a slightly different audience and it fits my budget, however every author will have to make a different calculus. It maybe you want to subscribe on a month-by- month basis instead of for a full year.