Hi from the UK,
Nice review Steve, all Weihrauch airguns are high quality, and their spring guns are my favorite springers by far. That spring twang can be reduced to zero with proper lubrication of the spring. You guys in the States will have many suitable products to choose from. I spray a clear grease on my airgun springs, the stuff is called PMA Clear Grease with added PTFE, and is made here in the UK. It was designed originally for motorcycle chains, open gears and heavy machinery. It is best applied by removing the spring and spraying it with the spring guide still inside the spring, then leave a few hours or so until it becomes very tacky, then reassemble the gun.
It gives you a vibration free spring gun that sounds and feels totally amazing, with very little cost.
If you don't want to disassemble the action, it can be sprayed on to the spring via the cocking lever slot once the stock has been removed, but take care not to over do it because it can make the gun diesel because of the spray carrier that is in the lube (this has to dissipate from the lube before it becomes real tacky)
Hope this helps.
Steve.
. Steve