You really need to be familiar with third party listing platforms to use Vendio because they really don't like to help much. It's understandable that being on the west coast, it might be hard for someone one the east coast to get help until around noon, but even still, once they actually start, you're still left waiting for someone to respond to you.
They are still pretty buggy for a company that's been around awhile. There are a lot of little things that it seems like you should be able to do, but for some reason or another just simply can't. The automated uploading of bulk inventory only goes so far. You still need to change each and every item so that the correct eBay specifications are in place. If you don't, you simply can't launch the items to eBay.
I would say if you're a listing a lot of items, just use Turbo Lister or something like that. These guys are more for the mom and pops that aren't spending company time and money being paid by the hour.