Well, it saved me tons of time transferring all my ads to Shopify, but it's made up for it somewhat in the issues I've had since the transfer:
1. No inventory update: if I sell an item on eBay or modify the description, the ad on Shopify will not refresh. So sold items are still buyable in my shop (and I can't sell them! I dont have them anymore.....) and the improved ads are not mirrored on Shopify.
2. Import function will import items already sold on eBay. Again items are in my shop that I can't sell.
3. Since this app doesn't update modifications, I tried doing manual imports so that the ads will appear in Shopify as they do in eBay. But every last ad + ads for deleted and sold items will all import again, creating multiple ads of one unique item. Then I have to go in and delete 50 items by hand.
4. And there are more problems that I dont have the energy or will to list. So I won't. Shopify uses this neglected and half-formed app as a selling point and for that I give a big thumbs down to Shopify.