Yeah, but 600 in the HAH is the impressive territory!
Now that you've broken the 500 barrier, you'll get more and more comfortable going further.

The HAH very reliably lights up the idiot lamp at 13 gallons burned- I've never had it miss by more than a quart.

The most fuel I've put in was 14.8gal, and the furthest I've driven was 545miles, I think.

The mpg gage is accurate and consistent enough such that I confidently believe that as long as it says my tank average is >36, I can roll off 600+ miles and still have a 1/2gal cushion sloshing around. The only reason I haven't is the way my commute route is structured. I'll push for a 600-mile tank this tank- I'm 1/2 through and sitting at 36.8 now.