I've got a Contest active shell and I like it a lot, but can't help when comparing it to a soft shell. It would pack down smaller for sure, but it's not that packable because of the liner.
I went for it as I thought it would maybe have a wider range and be a bit more versatile than a Phantom (which I might buy this winter anyway). Keeps me very comfortable with a base layer and jersey underneath, not really tested in the rain though. Also at the time I couldn't help thinking a Phantom would be too similar to a Windstopper climbing jacket I have, which I couldn't imagine riding in for longer than 5 mins without melting!
Actually just thought of one minor niggle: there's no drawcord on the waist, and if you have a couple of bars or something in the back pocket it can make it hang in a slightly odd, drafty way sometimes.