I have tried ProStores twice now, once when it first became available and the second time after the recent upgrade. I found the initial setup not to be very friendly or intuitive. They do have tutorials and manuals but plan to devote a lot of time just understanding the process. Once you get in the mind sense, then you are ok. They do have wizards but as with all wizards, they don’t always provide enough information for you before you check off something. Froogle integration never worked for me.
You can upload and export products. This part is very nice once you know how to use it. You can even create categories on the fly with import. You can export a tab file for you to use as a template. Cut and past your data into it and import it. You can FTP your images. Originally they required you to submit a large image and a thumbnail image but with the new version, it can create thumbnails from the large image. Nice improvement.
I am involved in selling through a fulfillment service. The biggest issue here is inventory level being maintained accurately. In order to do this, you have to manually update your inventory levels or export your data to a text file, delete all products in your store, update your text file with the new inventory levels and then import it back creating basically new inventory. Do this on a daily basis and you will have current inventory levels. If there is another way, I was unable to find it. Takes too much time too much room for error. eBay integration is easy. Visitors can see your auction on your website & it is easy post your items to eBay. I use calculated shipping. Unfortunately, there is no way for the looker to calculate the S&H because the eBay calculator is not available nor can you add it manually. The shipping calculator at ProStore is only available after the auction has ended and the buyer is directed to the store to pay. Like eBay, they have a “final value” fee.