I put the brush guard on my 580 when it was new. The first day I put it out in front of the house a 1x12x10 pine fascia board that was being pulled off came down and landed on the tractor. Luckily it hit the brush guard and did no damage. I also have no issues with the fact my 580 isn't EFI. I think far too much is being made of the EFI on smaller machines like the 590/580. I have no issues starting in below 0 degree weather, I can run all day on a tank of gas, and the little bit of extra HP derived from the EFI doesn't amount to a pee hole in the snow.I see what you mean. JD does make it a bit confusing. What used to be called a weight bracket is now called a bumper. Like you said, the only option now is the brush guard. I was never a fan of the brush guard as they designed it where you have to remove a hairpin clip and pull the rod out every time you need to open the hood to check the oil. For that reason I installed the standard bumper on my X500 which seems to give adequate protection.
You are right about the foot pedal. It's not too bad with a mower deck (I have a 48" deck) but with something like a snow blower it would get old fast.