I mostly liked the sale tool, where I put my whole shop on sale. I found it easier to use and more accurate then the EtsyOnSale app I tried once before. This is also a better value for the money I think, and it does Facebook, Twitter and Pinterest posting, which I pay another app for as well. I am probably going to cancel the EtsyFu service and just use this since it works just as well and its all in one service with the sale app and the analytics feature is very nice. It is pretty much multiple existing Etsy apps all rolled into one with a nice easy to use interface.
I tested it by using it, then not using it. The "not" using it was hard. I found it much easier to schedule the posts, then forget about them. I did wish that I could have put more specific information for Etsy teams on Twitter so they would be caught by them better. but the pictures worked extremely well. I found I expanded my target audience using the system, and sold more, which is the bottom line.