Interesting that they changed it again. I'm not sure I'd get much , with the forth temperature range. For me, there are basically typically three ways I use my PG500... one is cooking somewhere between 170 and 280F, with 225F to 265F being the most commonly used sub set of that.
I almost never use my grill set above 500F. I find that if I set the grill to 500F, the direct searing area will be 800F easily. This with a HHT of just 60. Anymore, I never run my grill above HHT 75... except maybe if I was trying to direct grill in the winter.
So, the other range I uses is about 350F... oh, that's not a range. Well when I cook chicken, I do it with the grill set to around 285F, that will get my upper shelf area about 330F, which is the temperature I like for chicken.
If I make a pizza, I might run the grill set to 500F, have HHT set to 55, the upper shelf will easily hit 650F on a nice day when set like this.
Anyway, it is interesting they added a fourth temperature range.