Ken - one of the guys in our club tried one and the few times I saw it, it seemed down on power. I don't know the exact numbers but it appears bigger and heavier than the .26 but I don't think it's anywhere near the power of the SAITO.
Keep in mind, however, that this is just one occurence - hardly a good statistical model.
I suggest you forward the question to me and I'll send it out to the 4S mailing list - maybe someone can offer more information.
Bob Z.