I drove several machines of all colors and even the same model Kubota’s and all acted different. Appears to be machine specific. I drove one B2400 that was abrupt even if you tried to be gentle it still gave you whiplash, and another B2410 that made rolling stops no mater what you did. I ended up with a B2410 that is absolutely perfect, while mowing I can drive right up to a fence post within a ¼ inch of it without hitting it with no practice and there is no jerkiness whatsoever forward or back. Mine has some type of device I can see attached to the pedal linkage that appears to control that. I have only had it a couple months and still learning about it (no service manual) but it appears some type of device with a small hole drilled in it that allows air to escape slowly therefore controlling the speed of pedal travel? This device resembles a small corrugated plastic tube. I don’t know for sure if that’s what it does, but from a quick look is my observation. I’ve heard others say there was an adjustable spring but I’ve not noticed one on mine, but then I haven’t looked that closely because it works so well. From my experience they are all different in the way they drive, if that is adjustable I’m not sure yet. Also a drive on asphalt or concrete is not anywhere near like on dirt, will be far harsher, as will be when in 4WD.