I been living off grid for over 20yrs and have 2 Trace 4024 inverters that are synced, however when we set up my brother's system about 10-12 years ago, we set him up with outback equipment being as Trace was now Xantrex and I was unsure of quality and reliability. I currently have pretty close to 5Kw solar with a small wind gen, with lead acid battery storage but I recently acquired 12 each 435 watt panels that I am going to add to the system. I was seriously considering up-grading the critical equipment being as it's 20+ years old. But, I have noticed that only a few places now sell outback, and most of the inverters up in the 4Kw range in the various brands are 48VDC which means that I would need to re-configure the complete system and add another set of batteries (current batteries are only 3-years old). So the quandary is what is the most highly recommended / best reputed brands of inverter/charger on the market. My Trace units have never faulted all I have had to change cooling fans 2X is all in the 20-years.