I would have put mine down as "other", but since there was no such option...
I use the S&SS version that can be found in Relics and Rituals 2. Things go beyond "totally different" in that world. Here's how:
First use the Psionics are Different rule and then add the following.
Dispelling and Negating: Doesn't happen. There are no spells to dispel or dampen that cross the border between Psionics and Magic.
Mind-Affecting spells and powers: You got a racial bonus against magic (dwarves: +2 against spells and spell-like abilities)? Doesn't work against Psionics. Exception: charm, compulsion and mind-affecting bonuses function just fine.
Spells and Power Resistance:
SR doesn't protect against Powers and the same is true the other way around.
The Scarred Lands have very few psionic creatures so there aren't all that many to be faced anyway. Unless a party specifically goes out of its way to find psionic stuff I usually throw a maximum of one psionic NPC their way per' campaign, and depending on the circumstances maybe half a dozen psionic creatures.
It just keeps things very interesting to introduce a bogey man whose Powers' the characters can't detect, counter or explain in any reasonable way. It also makes Psionics the most hated capability in the whole Campaign Setting. Basically everyone has a "kill on sight" instinct for psionic characters. Of course only the heroic or the very stupid actually try to kill psionic characters. Since they are so rare they also tend to be fairly powerful. Most people just run for the hills, while they are screaming for help. Not that your common farmer can really make a difference between psionics and magic. On the other hand Sorcerers are hated almost as much as Psionic characters, so it usually doesn't make much of a difference. Rogue wizards are very rare, since their behaviour and conduct is tightly monitored and their lives are fairly well controlled. Your average wizard works for some kingdom as part of the military.
Note that the above statements are generalizations, and they don't apply everywhere in the Scarred Lands. Just for most of the "civilized" world...