The system that both of these gentlemen propose is workable, I suppose, but I believe it has a fatal flaw.
You see, if characters have a perception of "Good" or "Awesome" or 10 or 3π or whatever, the DM knows what that number IS.
She can set the value of the hidden object to be Above, At or Below the value of the character skill.
Do I want the characters to find the item easily? Set the value low.In the end, the game is controlled by the DM and she can decide, up front, how the search is going to go...
Do I want the characters to roll some dice? Set the value equal to their ability.
Do I want them to miss the item unless they search? Set the value high.
They find it, they roll some dice to find it or they don't find it.Here are the ways I work the system and how you might want to work it too.
If I want them to find the item, I just put it out there. If they say "we search the room," they find the item. Easy peasy. This is the same as setting the value low. This seems too easy, I know, but anyone who has been running a game for awhile will attest to the frequency that players forget to search rooms. Maybe they are running from a monster. Maybe their characters are hurt. Maybe they just forget. This isn't necessarily a gimme, in other words. :)
If I don't care one way or another, I roll the dice. A large group of people searching for secret doors (or hidden stuff) can be simulated by one percentile roll. See this post. It takes one turn and I roll for wandering monsters. They can try again if they'd like. Takes more time and another wandering monster check.
If I want them to work to find the secret, I don't leave it to a random roll. I rely on player skill in a couple of ways: keywords and puzzles.
|Say the secret word and you find the vorpal sword...|
If I want things to be especially challenging, I create puzzle for them to solve. You might want to use the method I've created for Knockspell #6 (go get a copy! I don't get any kickbacks!)
I've also used the Soma cube puzzle (got it from my Grandpa years ago...)
Lastly, you can actually create a procedure that the players must describe their characters performing.
For example, in a recent game, there was an engraved displacer beast carved into the wall around a secret door. The secret door was apparent to the elves in the party (I rolled dice) but it wouldn't open. The players said they would search the other walls in the room. Lo and behold, kitty-corner (!) from the displacer beast was another displacer beast carving. Pressing upon the tentacles of the second carving opened the secret door behind the first.Well, that's how I do things. YMMV.