While it's obvious there are many common feature missing, i have few feedback (after checking it for few minutes without creating account)
1. Your website currently only show price of goods on satoshi unit. It'd be great if price (in fiat unit) also displayed.
2. When modify "qty" of item on cart, it's weird the page is full refereshed. In addition circle button "X" only reduce quantity by one, rather than remove the item from the cart.
3. There's no page which give information about website/purchase process, such as fees and minimum confirmation requirement.