Just got my 18 posts back and am extremely satisfied. Quality of link juice is high and these are sites that should pass a manual review quite easily. There is A LOT of effort going in to making these high quality and these are not like regular private blog posts.
This is probably the highest quality you will find available.
In terms of serps I've seen a very big effect. Some of the sites are very low OBL at the moment so that might skew the amount of link juice I am receiving however from reading above max OBL will be around 30 which is ok to good.
I also love the pact that they are niche specific and that helps to keep the sites looking clean and white.
I almost don't want to recommend it as I want to keep them all to me but the member has put a lot of work in to these and deserves to do well.
+ Communications are great and plentiful.