On any solar panel you lose efficiency in the heat during the day. By putting good quality system on in conjunction with your inverter, you'll get a much better efficiency rate out of a top end panel than you will out of a bottom end. So that also reduces the time for it to pay for itself, your return on your investment. So the hotter it gets, the less efficient it is. So in the middle of summer, a lot of the cheap end systems actually close down. They turn off because they just cannot handle the heat. So you put a good quality system on, it's going to still perform, but it's not quite as good as what it would on a cooler day.

You will produce more power with the top end system than you will with the bottom end, and with a good quality inverter you'll still produce a lot more energy than you will with a bottom end of a system.