The heaviest I ever pulled off the floor was 470 sumo style for a single, over/under grip, no straps, just a belt and chalk. That was some 14 years or so ago, just before I decided to concentrate on rack pulls.
I got away from sumo style after doing it for a good decade or so because I felt like I was mostly working hips, thighs, grip, and traps. And I have very rarely done conventional stance deads off the floor in the last 15+ years, because they just don't feel right - it seems as though they put my lower back in a position making it too susceptible to possible injury.
I will occasionally do regular deads off the floor maybe 1-2 times a year with moderate weights for a few sets of 4-5 reps, but it's very unusual - this is usually done on one of the rare occasions I find myself training in an unfamiliar gym that doesn't have a power rack available.
I've been doing rack pulls in the power rack with the pins several inches below the knees pretty consistently a couple of times a month for the last 14 years or so. I've gone as heavy as 595 for a single with an over/under grip, regular stance, and just a belt and chalk.
The rack pulls seem to really hit the overall back hard without my huge thighs and butt doing too much work. And the ROM is just a couple of inches shorter than doing them with the conventional stance off the floor. Those couple of inches I take out of the movement seem to keep my lower back from rounding too much and getting me in trouble.
I do these every other back workout, which usually means I do them no more than twice a month. I keep the reps to 5 or fewer on all sets.