The main issue isn’t that one modality requires more or less weight than the other—the same weight will have a similar effect— the issue is that you will need to condition yourself to vac hanging to avoid blisters and similar vacuum-related injuries so you will have to drop your weight and work your way back up over a few weeks. There’s also a learning curve with vacuum hanging setups, so it helps to start low and incrementally increase your weight to learn your way to optimize things and avoid these injuries.
There is probably an upper limit to vac hanging based on your equipment and conditioning, but I routinely hang over 10 pounds with mine. Some guys say 20 pounds or so. I’ve not gone that high and hope never to need to do so.
I think vac hanging is way better than compression: less painful, easier set up if you use the water trick (as opposed to taping) and no need to take breaks every 20 minutes like with compression. I can hang my whole session of up to 2 hours with no break.
Lots of resources here on how to best do it, but feel free to ask questions if you need to.
Best of luck!