I like Seller Tools ease of use. I was able to get this going without much effort. It was also easy to understand. As a new Etsy seller a lot is confusing, but this wasn't.
I loved the fact that Seller Tools helped me out to increase favorites number of my shop items. This lead to a 3 sold items. I also did not have to create coupons to make a sale and the new sale price was set automatically for each product.
It's amazingly convenient for posting to my shop's Facebook page! I just set it up and then forgot about it which is awesome cause that's the whole point, to save me time and energy promoting my shop while I can direct my attention to other things!