I did not play the 3.5 edition of D&D, so I don't know how faithfully this product ports those feats to 5e. I agree with others that the fee (even at $8) is too high for the information provided. The product looks professional and it contains good ideas that can be used to develop 5e feats for use in your campaign, but I would consider perhaps 30% of the feats in the book to be usable as "plug-and-play" 5e feats. Some of the feats are too weak, others are too strong (too weak is more common). Also, some of the feats are variations on the 5e PHB feats that are slightly different, but not significant improvements.
3 stars because the book includes some good ideas and concepts that can be used to develop feats you might not have thought of on your own.
[3 of 5 Stars!]