During the life of Solar Wholesalers we have imported and sold a number of brands of solar panels , including German panels, American panels and Chinese made panels.
In total we have probably sold around 40,000 individual solar panels and over all of this time I have only ever seen a few single panels with a fault (and surprisingly enough one was a premium American brand).
Of the 40,000 or so panels we have sold and installed around Adelaide and the Illawarra region of NSW probably 25,000 of them have been from China and we have been generally happy with these panels.
We did recently have a bad batch of panels we spotted and the manufacturer replaced the entire container, we were happy with there response to that issue they were as professional as we had always hoped they would be if we had an issue.
Mind you we have always bought from high quality Chinese manufacturers such as GCL, Sunrise SolarTech, Suntech, Schutten and Lightway.
The other surprising thing we have noted over the last 4 years or so is that we have found no real difference in performance between polycrystalline solar panels and mono-crystalline solar panels. Many solar power companies in South Australia try to convince clients it is worth paying a premium for monocrystalline panels over polycrystalline panels but in my experience there is no real world difference. We stock both but I think this is a point worth letting people know.
See our discussion What is the best type of solar panel.
Our main brand of solar panel we like to use are the GCL 250watt . GCL has state of the art facilites in China and have offices in Australia and also offer third party insurance policy on their warranties.