Got the itch for another gun.

Great choice. What configuration are you looking at getting. I really like the .177 at just over 13 fpe . In .22 the 410mm barrel on the K models is long enough to make power up to 30 FPE but the shot count really suffers. My favorite is the laminate thumbhole stock over the S but they all shoulder real well. I would suggest getting an aluminum air cylinder from eBay I believe the 298mm cylinder is the one I went with. Fits the K model just fine and increases the cylinder volume by a bit to help with the shot count. 
 
Hi Marley5,

I shoot the .177 HW100 which is close. The magazine is wonderful and the rifle just shoots and shoots.

If you like a lower scope on a rifle, it is possible (within the limits of the objective) to drop the scope down as the magazine is low in the gun. The hammer strikes the valve through the center of the magazine so the magazine can be low. I find the magazines easy to insert and remove.

Some folks mention it is mechanically complex. I'd call it modular. I've played in mine (because I wanted to and not because it needed it.). I've dialed the regulator down to 85 bar for low power shooting. It is easy to work on. Information and parts are available if you want to tinker.

Oh. The moderator. In .177 it is quiet. Bet the 22 is also. I've heard good things about the HW100 moderator. I am running the 600mm barrel which helps reduce noise.

The removable air tube is an interesting hold-over from earlier days. There are oversize aftermarket air tubes available but I've been warned to use HW100 end-caps as the aftermarket end caps can leave something to be desired. In a pinch you can swap an air tube out in the field for additional shooting. It just screws on.

I'm sure other HW100 fans will pop up shortly.

I like mine so much I've got an eye out for another.

Enjoy,

Nugria