In the past year, Pandabuy has taking the Taobao/Weidian world by storm, and they continue to widen the gap.
They don't necessarily do this because they are cheaper, their many driving force is the affiliates program that attracts tiktokers and redditors. You can generate affiliate links for everything, which has lead to people spamming the links on the web.
Pandabuy is probably the only agent that has features that Superbuy didn't have in 2017. They allow you to view QC pics and item weights of items other people bought (Cssbuy and Superbuy have this too). They offer a compelling rewards program with cnfair (ask me anything about it).
After Superbuy, the website is the second best, they have little to no downtime.
The Pandabuy service just works, which makes them a contender for best agent. I would let it come down to a price comparison with the shipping calculator.
You can make a Pandabuy account here.
added: 6/26/2023