Your logic favoring the Monolith as a cost effective power upgrade adds up. Double the power will get you ~3 more db of low noise output compared to the 7000x.

The Outlaw might differentiate itself if you have a lower noise floor listening room or a speaker load that benefits from the differential amp design (additional benefit when feeding a balanced signal). If you've allocated more total system cost to the speakers and room then the Outlaw may be a proportional upgrade.

Both amps have ATI family heritage, good power supplies.