I have used wegoshop.com 7 times and I highly recommend them. My thoughts:
I create my own list with brands and sizes rather than shopping a "virtual Aisle" I very much prefer doing it this way. I can indicate whether I will allow substitutions or not. I have had the shopper call me on my cell from the store and inquire about a substitution.
I can choose where the shopper will shop.
There is no minimum order amount and GG has one.
The individual item prices are not marked up and I receive the original store receipt. GG marks each item up. But I think wegoshop's delivery fee is higher. I think they end up costing about the same amount. We saved the delivery fee on just the difference in buying a case of water vs buying bottles at Disney.
Wegoshop gives me a 30 minute delivery window and has always been right on time. GG has a 2 hour delivery window.
I have Wegoshop deliver directly to my Villa, not Bell Services. I go over the order with the shopper in real time. I do not have to tip Bell Services again for delivering my order.
We usually order: Fruit, Juices, Coffee, Water, Soda, Beer, Wine, Breakfast foods, Cheese and Crackers, Chips and Salsa, other snack items.
I think both wegoshop.com and Garden Grocer are reputable services and both have lots of fans.
Good Luck