Stealth rank questionFollow

I have a question regarding Stealth ranks (as you probably gathered from the title). I got into a discussion about WoW with a co-worker (I didn't even know he played WoW, let alone was a hard-core raider on his rogue), and he told me he was annoyed that the Burning Crusade didn't add higher ranks of Stealth, because the higher ranks gave an improved chance of avoiding detection.

Now, from everything I've read, the things that affect stealth detection are the rogue's level vs. the detector's; the Master of Deception talent; the Night Elf's Shadowmeld; and certain talents/spells/abilities/items (Heightened Senses, Track Hidden, the felhunter's Paranoia, the various epic engineering goggles, etc.). The rank of stealth used has no effect on being detected, unless you want to count being able to move fast enough to Cheap Shot your victim before they can react.

Is my coworker right?

Your co-worker is mistaken, you get no "stealth Bonuses" depending on the rank of your stealth, It's based off your level (+ or - stealth modifiers)

A rank 1 Stealth offers the same level of stealth as a rank 2 Stealth (assuming it was possible to use two different ranks)

The ranks only change your speed, not your stealth level, Stealth level is based off character level (much like lockpicking and poisons, 5 per level)