I don't disparage Decelerator pads and mercury recoil reducers: I have both installed on my .375H&H. That rifle (700 remington classic) was very light, and I found the recoil uncomfortable. That might also have been in part due to how I held the rifle The mercury bottle helped quite a bit. I have found past pads still make shooting off the bench at a range more comfortable -- even for my .375H&H with the recoil reduction stuff.
A prior .458 win that I owned had taught me that the cartridge requires respect. That's why I got the extra past pad. I'd learned about the tingling in the arm first hand from that first .458 win rifle. So, I'd never shot my 1H without the pads for my first outings. I did fine the Past pads very effective at reducing recoil -- shooting 20 rounds was not uncomfortable. However, the last time I took it out, I decided to shoot it without the pads to see if it was really as bad as I remembered. I found that the recoil with no recoil reduction, no past pad, etc, was quite manageable. Not even a bruise after several shots. My conclusion is that recoil reduction isn't something I'll bother with for my 1H. Its fine for hunting as is. And, I will keep shooting at the range the way I do with all my rifles (though I don't bother with the past pads all the time, I still like them). Suffice to say I was very pleasantly surprised how manageable the unreduced recoil of the 1H .458 win could be IF I had just learned to hold the gun better when I'd begun shooting .22's (its harder to unlearn habits that have already been established -- especially adjusting shooting positions, keeping good fundamentals while tweaking things, etc).
I figure it is worth trying some simple things -- like holding the gun differently -- if it can save some money, and the time the rifle is away at the gunsmith's (not to say that gunsmiths are not worth their hire!).
Dan