This test is awesome. It has me dead on. I'm an ISTP . A few highlights:
"ISTPs are equally difficult to understand in their need for personal space, which in turn has an impact on their relationships with others. They need to be able to "spread out"--both physically and psychologically--which generally implies encroaching to some degree on others, especially if they decide that something of someone else's is going to become their next project."
"These territorial considerations are usually critical in relationships with ISTPs; communication also tends to be a key issue, since they generally express themselves non-verbally. When they do actually verbalize, ISTPs are masters of the one-liner, often showing flashes of humor in the most tense situations; this can result in their being seen as thick-skinned or tasteless"
"ISFPs may be quite charming and ingratiating on first acquaintance, flowing with compliments which may (or may not) be deserved. On other occasions, the same individual may be aloof and detached."