In my experience carvin rates their cabs a bit optimistically. The neo 10.4 I played thru wasn't much if at.all louder than a behringer 4x10 and I hate to say this.but the behr seemed bassier and fuller
The power rating of cabs has nothing to do with how loud it will sound.
A cab's power is a maximum amount of power that the cab will handle.
The wattage is the total of the power handling of all speakers in the cab. Two 100 watt drivers = a 200 watt cab.
To compare cab loudness, given equal power applied to the cab, the number you need is Sound Pressure Level, SPL.
These numbers are usually in the 90 to 100 db range, give or take a few db. They indicate speaker sensitivity.
The higher the number, the more sensitive, the louder it will be.
A +3db difference is twice the sensitivity, not twice the loudness.
You normally need at least a 10 db difference for a noticeable (significant) difference in apparent loudness.
The design of the cabinet can also affect how loud it is. You should not expect to hear much difference between two cabs with the same compliment of speakers, two different 4x10 cabs for instance based only on the cab power rating. The same with being bassier or fuller. That is a function of the speaker design and cab design. Not the power rating of the cab.