Flash is no doubt universal, while spriter is new kid on the block. I came to know about it only on scirra forums. I believe spriter has a plugin only for construct. In that way it is very limited. I am anyway working with it right now to understand its pros and cons.
I have no disrespect for the software or the developers, nor I am saying it is not worth it, who knows it might be even better than Flash.
I did mentioned above : "Use Adobe Flash if you are going Adobe route". Spriter is not included in Adobe route
I have worked with all major 2D animation software including toonboomstudio. I am also currently writing a book on games and would definitely include Spriter in it if it is worth it. That is why I am testing it right now.
I did send them an email a month back, no response till date. Anyway no hard feelings man, I do hope spriter can pass the test and actually beat flash. I hate Adobe's new cc model.