Didn't read all the replys. When I saw the system you were looking at for your gun all I can tell you is there is no comparison! I have that system on my Browning O/U and can shoot that gun all day long with no problems at-all. Yes, it is a lot of money but if you want to shoot 100+ shells a day it is well worth the coin!
I have a mercury recoil reduction system in my wifes 870 plus a nice cushy recoil pad and it made her gun much more tolerable to shoot a round of 100. Still is no comparison to my Browning.
I have the same cushy recoil pad on my 1100 and the Browning is still a gentler gun to shoot.