It's a nice plugin but the search is a hit and miss affair for the Amazon UK store.
I tried to add some bat detectors to my store - with WP ZonBuilder I get about 12 detectors with Prosocate I get 1 - the Discovery Channel toy rather than real bat detectors when searching under electronics. I get nothing when searching under Gardens and Outdoors and when searching under all I get 7 items associated with bats including books.
This has happened under a number of other keyword searches where the items returned are substantially less than are picked up by other similar plugins.
I think if you want to run broad range stores then this is an OK plugin but if you want to target specific items - I run wildlife sites and so want to include quite specific products - there are probably better ones around.
That said - this is a new plugin in the early stages so I will certainly be keeping an eye on the development as it offers some excellent options - such as variables - that are not available with other amazon plugins including premium ones.
Update: There's also no option for importing a list of ISBN numbers to build pages that way. I was going to test it on one of my wildlife sites but had to uninstall and go back to WP ZonBuilder because so many products just could not be accessed through this plugin.
There's also no option to use the numeric value of nodes to try and overcome the lack of node listings in the plugin.
Using the keyword search I'm just getting about 5% of the available products being returned and in many cases I'm not getting any product returned.
It's a nice attempt but I think there's still quite a way to go before becoming useful.
Update again: to keep up with developments I bought the Pro version. It appears most of the issues I have above are dealt with in the Pro version but there is little documentation to show the difference between the free and the paid for version.