My personal number two.
+ they got soooooooooo much stuff
+ they often got exclusive deals for figures that you can't get elsewhere without paying a lot extra, or additional bonuses such as face-plates etc
+ they are reliable
+ they know how to invoice so you get your things faster through inspection
- unknown shipping rate for pre order, hard to calculate the end price
- their ordering/payment processes require a lot of extra confirmation, several emails, logging in after clicking on links and so on - it's a bit antiquated
- they send out merchandise in packaging that is way too large and way too expensive*
-customer service requests usually end with "we are sorry but can't do anything"
*Examples: Rubber strap box in a package that would fit a figure. Desk mats are being sent out laying flat. I know they do this because a minority of collectors want mint packaging, but it bothers me to pay so much shipping.
Conclusion: AmiAmi is my go-to place for all anime merchandise. Sometimes I also order their exclusive deal figures. I don't like that I can't see how much I will end up paying for pre-orders because the shipping costs only appear when the item has arrived in stock. Anyway, it's one of the best shops.