I'm using A1RMs with no squeal. Some pads have more tendency to squeal than others, but in many cases its due to poor installation. I use them for track and they're fine for my setup, which has some cooling at the front. My guess is that A1RMs will be better on the track, but worse on the street, than Ultimates. Give them a go. If you don't like them for street, get some full street pads and swap as required.