I think the ISEE may be more difficult to score well.
My daughter took the SSAT and my son took the ISEE last year. I�m not extremely knowledgeable about either, but I believe that the SSAT is a more �run of the mill� test and given to a more general population pool while the ISEE is often the exclusive test used by the more selective schools. As such, there is commercial opportunity and many test prep businesses to help get kids �in� these schools. I learned this fact after my son took the test cold.
I didn�t feel the need to purchase even the official ISEE prep for less than $20 at the time we signed him up online. We are used to seeing high numbers on any grade level test he takes and were quite surprised to see average percentiles for the verbal (analogy) portion of the ISEE. Math was high per usual. After we received the results, I did a little research and found a few articles and many advertisements and came to the above conclusion. DS probably redeemed himself for admittance between his ISEE math portion and required essay. He also wrote thoughtful answers for the extensive application and I would assume did well during the interview portion of his evaluation.
A 2E consideration may be that the ISEE doesn�t allow calculators while (I believe) the SSAT does. While I�m thinking about it, I don�t believe the SSAT had an essay portion either.
