We've taken the plunge and are trying out the blue point Siamese. So far, so good, just a little swearing in the middle of the night when he got too close to Taffy, but otherwise they're cautiously checking each other out and have touched noses. Nothing timid about this boy, he's been checking out the whole house.
He's been a bit of a surprise so far. First surprise - he actually appears to be a Siamese, not a colourpoint mixed breed cat with Siamese ancestry like Taffy. Mind you, he doesn't have the baby-cry voice, so perhaps he isn't completely purebred.
Second surprise - he's HUGE. Only 12 pounds, but long and stretched out, like a panther. When I've seen purebred Siamese at cat shows, they always looked like really small cats. We had to swap a plastic storage tote for the litter box we'd bought for the previous cat as he couldn't fit in with the cover on and hurled litter all over the furness room with it off.