After 285, I'd recommend going down to 10lb jumps on the DL. My experience was that jumping 20lbs on the DL was super easy until it was suddenly very very hard. 265 was the last number I hit with 20lb jumps.
But I'm only pulling 320 so my opinion isn't worth very much. Between 265 and 320 I made a ton of dumb mistakes and wasted several months.