I would strongly disagree about the pad noise. I have been driving with A1RMs on the front brakes with my s14 for about 10months. I drive at least 3 times per week, if not daily. I only experience braking squeal rarely when pulling up. Overall, brake squeal isn't as issue with this pad. I will conceed pad dust is a major factor but probably a lot more noticable on white rims. Cold performance is hard to tell since my tyres also have trouble in the cold, so cant really tell. though i suspect having both susceptible to the cold doesn't help.
Unfortunately HPXs don't last on the track, even on the rears. I thought I could get away with them but after two days at Phillip Isand and 3 months of semi-regular daily driving, they are already gone.
Will be switching back to the A1RMs when I have the time to change them. ( Still using A1RMs on the front. )