May be its my imagination but the a air shocks had a more plush ride compared to the dial shocks on the m8.

 

Shocks are supposed to be better than the previous generation -

Experience the ultimate in superior ride quality with these premium Touring shocks. These shocks utilize a single tube, nitrogen charged design.

• Low Ride Height version
• Offers enhanced compression and rebound damping compared to the Original Equipment-style air adjustable shocks
• Provides a controlled yet plush ride with less bottoming
• Larger chambers (40mm diameter pistons and 14mm rods) allow these shocks to react more quickly to impacts - this keeps the tires tracking while minimizing harshness transmitted through the frame
• **** behind the left saddlebag allows the rider to conveniently modify the spring preload via a hydraulic adjuster
• Available in Standard Ride Height and Low Ride Height versions

Read here for more https://www.hdforums.com/forum/milwa...e-running.html

 

I've found the ride on the 17 and up touring bikes to be far better than anything I've pre previously ridden or owned with air suspension. Of course if you really think air shocks are better, and just have to have some, I'm sure someone can get you the whole rear shock and pressure line set for cheap. Have a couple sets myself, just gotta ask.