We've been using Affiliate Toolkit for about 1.5 years for two projects and it's time I praised it. We used to work with AmazonSimpleAdmin, but Affiliate Toolkit is so much larger and much more adaptable to our websites. I have tested some affiliate or price comparison solutions for WordPress since 2012, and none of them offer the full range of features of AT and the seamless connectivity to Affilinet, Zanox and Ebay (besides Amazon). The nice thing about an affiliate toolkit is that the plugin is actively maintained and developed, which is not the rule for such plugins. Also, the plugin is very well documented and everything is explained in detail, which makes it easy for me as a developer to understand functions and implement exactly what I need.
I could imagine that at first one is a bit overwhelmed, because the plugin really has many features (that's what I was at the beginning). But if you look through it after a short time, there is at least no known alternative for WordPress, which works so well.
In addition, Christof provides truly incomparable support. I have already contacted him 5-6x for minor issues and feature requests and his answer always comes within a very short time (usually within minutes, from and to only in 2 - 3 hours). In addition, he has implemented two of my suggested features immediately in the next update, for which I say thank you again.
Affiliate Toolkit (along with Advanced Custom Fields) is one of the WordPress plugins I recommend to any affiliate honestly and without restrictions.