I am tired of getting a sore shoulder every time I shoot my Guide Gun. I notice that Pachmyer and Kickeez offer prefit pads that are suppose to screw right on and provide recoil reduction. Has anyone tried them? Do they fit and do they offer any recoil reduction over the stock Marlin pad? It sounds like a good idea but I wanted to see if anyone had any real world experience before I ordered one.

I don't have any experiance with those particular makes. But past experiance has taught me, if you don't want to go to the trouble or expense of a custom fit pad. Then it is best to go with a "slip on."

I can't speak for Pachmyer and Kickeez never used them. I can tell you I've put Limbsaver prefit recoil pads on my 12ga and 7mm Remington Mag.
WOW!! what a difference in comfort and felt recoil it made.
One bit of advice, take the Butt Plate with you and match it up. I bought one that had my Rifle listed on the package and it was to small, back to Gander Mountain I went this time with the Butt Plate with me so I could make sure it was the right fit.