Aliexpress vs. Banggood:
I'm not intending to write about my personal experiences, as they will vary from customer to customer. It's rather a general consideration:
If one has to choose between Aliexpress and Banggood, please consider one thing:
With Aliexpress you'll deal with the retailer directly, whereas Banggood is like an Overlord "hiding" the actual suppliers, and taking care (..or not so..) of the CS for them.
The user interface in banggood gives a better overview and confirming reception of your parcel is quicker, but Aliexpress gives you the opportunity of a more differenciated feedback.
My personal experience is that the Aliexpress retailers generally react incredibly quick to your questions or complaints, whereas banggood shows communist tendencies
, meaning you'll deal with some encaged CS operator not remotely having an idea what you're talking about.
The Aliexpress vendors often don't know much more, but will quickly refer to someone who does like the "quad-guy" in their shop or similar.
Since feedback affects them directly, they're incredibly friendly if you communicate in a well-mannered tone.
Prices are comparable (Ali slightly less expensive), shipment maybe a bit faster with banggood, but there are Aliexpress-retailers which are incredibly quick. Quality control issues are common to both..