The best source of comparative data between a Roof Top and a Split System can be found on You Tube. "RV Rooftop vs Mini-Split AC | Shop Talk | DIY Truck Camper" video. It's a great in depth comparison of the two by an HVAC engineer that's presented in plain English with a spreadsheet comparing the data.
This is the direct link to that video: https://youtu.be/2rk4rANcaVg
Installation of a split would be a process but it is well documented by others so while it's not bolt on easy it doesn't require one to break trail. LG sells an inverter system window unit that's actually brilliant. If it wouldn't look so ghet..er..sketchy ..one of those would provide 14,000 btu cooling in an easy to install package for under $600! You can find them on Amazon for information sake.
In another forum the Houghton roof air units were recommended as a better alternative to Dometic and the like. Looks like they are a bit less noisy.
