I can't speak from experience, I've never tried the countervail version. If you read through the previous posts, the countervail is very muted, too much even.
the 2015 version, has amplifeel and parallel drilling, and the feeling is very plush, therefore I went with that model.
2013 version is similar than the 2015 version, has amplifeel, but NO parallel drilling. I have 1 as well, just a bit harsher than the 2015.
From what I've read, the v7 is very similar to the 2015 versions. I'll try one out eventually.
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