NTs vs. NFs: NT's are more logical and much less likrly to see the human side of things than NF's.
NTs vs SPs: NT's are much more intelligent, disciplined, and sincere than the average SP. I think of them as either manipulative bastard or target practice. I have a lot of bad experience with these.
NTs vs SJ: NT's are more innovative and often willing to come up with their own ideas than SJ's. The experience depends on the SJ. I positively abhor my ISTJ brother, yet I know a girl who is ESTJ and I adore her. She has a lot less T and a lot less J.
Your statement about SPs is ridiculous. If you think NTs are smarter than SPs on average, it's because you're only considering NT-specific forms of intelligence. I'm sure NTs score higher on average on IQ tests and SATs and so on than SPs, but that's because IQ tests/SATs are biased toward NT-type intelligence tasks. Intelligence is highly multi-faceted and expands geometrically, not linearly.
I suspect that in a field test involving real world tasks and hands-on manipulation of the physical environment, NTs would fail miserably against SPs, and it's a mistake to assume that these kinds of skills don't qualify as some sort of "intelligence."
well, I dunno about pitting the types against each other but I'll tell you what I think of each group.
NT - Probably the highest collection of genius and creativity one group can collect. However it's also probably the least socially adept group, might not be our faults though since we are outnumbered.
NF - Probably the highest collection of peaceful, diplomatic, creative, and artistic people. Can sometimes be overly sensitive.
SP - Probably the highest collection of party animals, always in the moment, great people to be around. Not very responsible though.
SJ - Probably the greatest collection of boring people, with a serious lack of creativity. However they serve a useful purpose of being responsible and family oriented, help keep everything grounded, but still boring.