I think it really depends on your ST. Some appear to be made better than others. I have never noticed any significant noise difference in mine with load imbalance. The biggest hit I probably have is a small microwave that throws 1.4KW onto a single leg. I notice this load on all the other items on this leg(UPS beeps), but have not noticed anything from the generator. I try to avoid imbalance as a rule, but mine dosn't complain about it. For that one single large load, I purchased a 240:120 transformer so that the microwave load can be spread across both 120 legs equally. I got lucky in that when I hooked up to my main panel(interlocked backfeed breaker), the breakers I can run when on generator power equal a ptetty balanced load for the genset. Balancing a panel is not particularly difficult, but you do need a clamp-on amp meter/probe and know your way around a panel... You can also do it by adding up loads, but you must be able to positively determine which leg they are on.