I recently got the AXE-FX III and also purchased a Crown XLS 1002 Power Amplifier to put it through. The cabinet I'm using is a Seismic Audio empty 2x12 cabinet. I am using 2 WSG Veteran 30 speakers in it. This video is just a few quick examples of some settings you can use that will improve the tone of the Axefx through a guitar cab.
You may notice as I did that if you use the stock settings in the Axe, which sound awesome for direct recording, it might sound somewhat muted though a power amp/guitar cabinet. It seems to often have a "blanket over the cabinet" sound. These few adjustments will make it sound brighter and clearer without making it overly brittle. Please let me know in the comments if this video is helpful and please leave any tips you may have!