My biggest issues with so much of the ebay stuff from China are the pictures are hijacked from some other listing or flat out stolen from reputable websites, the dimensions listed are often times not even remotely close to what is shipped and attempts to get clarification before bidding is often very hit-or-miss.
Don't get me wrong my mailbox is constantly filled with mailers from China; the prices on electrical components is crazy compared to anywhere stateside. You just have to ask questions until you are satisfied that you have a pretty good idea what you are getting.
I bought a set and nothing was wrong with them. I broke the inflow from being too hard on them (not a quality issue) but the outflow is still going strong after 4-5 years. Shipping took 3 weeks which is forever to me with aquarium products. The acrylic ones look very interesting though for the money. I bought some DIY ones in the LA area and love how durable they are in comparison to glass.