I first used AoB back in 2007 and loved it. Used it up until 2010 when I switched everything to FBA (AoB) wasn't set up for FBA at the time. Still not sure if they are. I guess that's my main question, are you guys setup for FBA. Would love to drop one of your competitors and get back 100% with AOB.
I use it for FBA. It's clumsy and I have to move back and forth between AoB and amazon, i.e. to get multiple FNSKU labels printed. Some features do not work well, for example if you sell multi quantities in one order, AOB will only deduct one item from your inventory. This has been an ongoing problem and they can't seem to fix it.
Listing on AoB is much easier/faster than on amazon and they have check boxes to list on FBA. They do not build shipments on AoB, you have to go to back amazon to do that.
Not the fault of AoB but multi channel fulfillment has been a huge headache on amazon. This is supposed to be a feature of AoB, the ability to list and ship on other venues, but amazon has not been timely with shipping and this can ruin your status on eBay.I've stopped doing MCF since I nearly lost my eBay account for late shipping.
AoB could be really great for using FBA but they need to add a lot more features that work easily. I'm still hoping to see some changes.