Arx is a reel built with purpose; Spey or switch casting a variety of lines with maximum line control and reliability. The continuing evolution of Spey and Scandi lines, shooting heads, flat mono, etc. demand a reel that can help prevent line snags while retaining the high performance you've come to expect from Waterworks Lamson.
Arx has a full cage frame that encapsulates the spool to prevent line from escaping or snagging in critical areas. Normally a configuration like this would do a good job at preventing line fouling, but would preclude palming the reel.
Arx is carefully milled on the bottom third of the reel to expose a functional palming section. Even the drag knob has been designed to provide optimal grip without exposing a portion of the reel to line fouling.