Here are my current life totals for each 6500EX as of today.
I have too many simultaneous construction projects right now, but eventually my plan is to split the garage, the house, and the shooting range cabin into three independent solar setups. I'm likely going to do this by purchasing an 18k, installing that into the house, then putting one of each 6500EX into the garage and cabin.
Few reasons.
1) I think this is the cheapest way to split the systems to be independent.
2) The 18k is more energy efficient, especially in idle consumption, which will increase the efficiency of the house where power is used 24/7 but night energy is low leading to idle power being a significant portion. The other two building I can shut off the inverters when not in use with minimum user impact and minimizing the idle consumption.
3) I now have complete confidence in the 6500s ability to run, and in the longer term I could buy a 6000 for the cabin, then move the 6500EX from there back into the garage and have 240V standalone in the garage. I do have a 240 welder in the garage, but I can use the existing subpanel to power that one item from the new 18k in the house for the interim.