*sympathetic nod*

So much depends on your particular child, and how s/he experiences the test-taking experience. Ask. What does he want to do? Keeping in mind that, all the way up until test day, I think you can cancel/postpone the registration to another administration date (check CB to confirm this, though), so there's an escape hatch.

My experience was that it was more awkward for the juniors and seniors than it was for the young test taker.

...pronounced like the long vowel and first letter of the alphabet...