If I can swing it next Thursday, I'll head to Philadelphia for the PV America East conference and check out the vendors. PWER has a larger booth there and may have some insight into the take-rate of their inverters going into Q1. Their leadership will be in commercial installations, really, which is where the benefits of buying one inverter to handle 1MW or more modules at once will drive the GW of installations. Commercial installers don't cheap-out and buy "Chinese stuff" to save money except perhaps modules which are dirt-cheap by the container. They may buy cheaper modules and the better inverters since that is the main point of failure - it's either "on or off".
jmv are the boarder who put up your own system? I would like to pick your brain. I went back through old posts but could not find them. It may be better to communicate in e-mail since this is slightly off topic.