My experience with this shop for 1 year is mostly positive and gets more positive as they improve service. Warranty experience is also good, so far my electric shaver had 1 of 3 razors broken and they refunded me 1/3 of a price; air mouse broke half a year after purchase (USB receiver not recognized with code 43 in Windows) I expected some technical advise, but they actually refunded me 1/2 of the price, they later offered me full refund, but I didn't bother as I used working battery from air mouse in other device.
I didn't send anything back and I hope I won't have to because it's very long and expensive procedure (they must refund shipment later, but still makes me nervous).
My latest purchase was Edifier W806BT headphones for 22$, which is great price. GB has very good bonus points program. Bonuses can be used to drop 30% of price which is the biggest percentage I've encountered in Chinese shops. Bonuses are easy to earn - 50 points for video review of a 1... 5$ products, and review doesn't have to be quality - just show product packaging look and operation.
The downside as with many Chinese shops is language barrier: there are situations where customer support doesn't understand your request for refund or order status and make a standard robotic reply.
For example they changed international phone number form and my phone was written without +380 code for Ukraine, which led to misunderstanding in the post office (phone numbers here are either typed with "0" or "+380" in the beginning because bare phone number doesn't work). It took very many posts to explain the problem as they told me I just filed it wrong.
There are opposite situations where I asked for technical help with getting items to work but was offered straight refund instead.
Also I don't like that they don't ship batteries to Ukraine.
I understand why people usually freak out at those standard replies and think they are getting scammed, but I have to say I never had to escalate my complaints to Paypal. I suppose people who aren't offered refund paid via other means.