Your declawing of your cats may have been "successful" and Im sure totally painless for YOU. Your cats, however, would tell a different story if they could talk. Declawing requires cutting off the last bone of the cats claw to prevent the claw from coming back. There is no humane way to do this. Its great that you left your cats in a vets care until their wounds healed, but the pain didnt end just because their little stumps were no longer bloody. Living without claws is painful for cats. They can feel the loss with every step they take. The reason a lot of cats (note I said a lot not all) start peeing all over the house is because stepping on the litter in the litter box causes them too much pain.
You are, of course, free to declaw your cat if you want and can find a vet still willing to do it. However, please dont try to delude others into believing that this is not a big deal to the cat. He will live with the pain of your decision every day for the rest of his life.
The following quotes come from two of the most respected organizations active in the humane treatment of animals. I know it will not do anything to change the minds of those who know declawing didnt hurt their cats. However, I hope that anyone who is on the fence on the issue (like the OP) will read these articles and decide to come down on the side of truly caring for you cat.
They don't realize that declawing can make a cat less likely to use the litter box or more likely to bite. Medical drawbacks to declawing include pain, infection and tissue necrosis (tissue death), lameness, and back pain. Removing claws changes the way a cat's foot meets the ground and can cause pain similar to wearing an uncomfortable pair of shoes. There can also be a regrowth of improperly removed claws, nerve damage, and bone spurs.
http://www.humanesociety.org/animals/cats/tips/declawing.html
Do NOT declaw. This surgery involves amputating the end of a cats toes and is highly discouraged by the ASPCA. Instead, trim regularly, provide your cat with appropriate scratching posts and ask your veterinarian about soft plastic covers for your cats claws.
http://www.aspca.org/pet-care/cat-care/cat-care-nail-trimming-101.aspx
This is an excellent example of alarmist propaganda masquerading as fact. In fact, the quotes you give say nothing about any of your original points. Nowhere do they state that declawing a cat will cause it to feel pain every time it steps into a litter box. Nowhere do they say a cat will live with pain every day for the rest of its life. Nowhere do they say that living without claws is painful for a cat. None of those "facts" that you mention in your first post are supported by facts from the websites you quote. They are your personal opinions.
The websites do give lists of possible side effects. Much the same way any medical procedure or medication has a list of the side effects or possible things that could go wrong. If you look up spay and neuter surgery on cats you will also find lists of side effects and possible things that could go wrong. You could permanently alter your pet's personality if you spay or neuter, did you know that? You radically remove a pet's means of reproduction, causing them to miss the opportunity to nurture their young, which they are instinctively meant to do, did you know that? Those are terrible side effects to inflict on a poor animal, don't you think?
My point is that most cats can be safely and humanely declawed with a minimum amount of pain and can go on to lead long, happy and safe lives as spoiled house pets. It is not always a given that any of the side effects you state as fact are going to occur.