I don't think their feeds compare at all with liveATC
I'd love to have it available on liveATC just to have the archives! Also, there are a TON of frequencies available at KATL/A80... there would be a heck of a lot to listen to! I think ATCMonitor only has three different frequencies?
Last time I listened to ATCMonitor, the feed quality was pretty wishy-washy... maybe it's improved?