I've used both and would recommend WeGoShop hands down!
When using Garden Grocer, I received freezer burned items, produce that was past it's prime, and the items were not packed well so many things were soggy or crushed.
WeGoShop has excellent customer service and will go to any store you choose (Publix, Whole Foods, etc.) to shop for exactly what you want - no limiting yourself to a preset inventory on a website.
WeGoShop will shop for fresh items with the same eye they would use to shop for themselves so everything is top notch (and if there are any snags while they are shopping, such as a requested item not being of acceptable quality, etc. - they contact you to discuss substitutions, etc.). The delivery fee is well worth it when you know that you'll receive quality groceries delivered in person by the individual who shopped for them on your behalf!
No comparison between WGS and GG in my opinion!