In reply to Keith Tanner :
Interestingly, the snow test I did wasn't in deep snow. It was on an inch or so of packed down dry powder. With the ABS on, it would cut in and reduce braking as soon as the snow started to groan under the tires (and you weren't really stopping very fast at that point).
With it off, you could get significant groan from the snow (and much faster stopping) without locking a tire. Leaning on the pedal a little harder past that point would lock the front tires and cause a significant drop in braking force. Pedal effort to achieve lockup was not just a little past the ABS engagement point, but it was quite a lot more pressure. I wish I'd had a brake pressure gauge on the thing when I did the test, as I wouldn't be surprised if it were double the ABS engagement pressure. Given all seasons on the same snow, I'm betting the ABS engagement threshold and lockup threshold would have been a lot closer together.
Fortunately, this is a vehicle with fairly high pedal effort (especially in cold weather with cold pads), so it's reasonably easy to find the traction limits with the brake pedal and not over-do it (leading to lockup) like a setup with low pedal effort. Low brake pedal effort in modern cars definitely makes ABS much more necessary IMO. FWIW in the winter, it was fairly rare that I'd trigger the ABS in the thing, but every once in a while I'd manage to. Without it, I've yet to accidentally lock a tire.
The other flaw with the ABS was rain. Hit a bump under more than very light braking on wet pavement and the slight drop in wheel speed from the wheel that hit the bump led to the ABS pulling a bunch of braking power for a 1/2 second or so. Kinda unnerving (and totally unnecessary).
