Honestly? I have no idea. That's what DD did to 'prepare' for them both. Mostly, for DD, this amounted to finding her "ideal" pace-- and for figuring out a strategy for the math sections to reduce errors in computation, which are the bane of her existence.
DD thought that the SAT math sections in particular were about "trick" questions. By that she means that prepping helps a TON with them, because you have to know the One Right Way of doing the problem-- there's no way to really leverage general math knowledge to do them a less efficient but still valid way. KWIM? Her impression was also that there were weird types of questions on the SAT just in general-- things that if you weren't prepped, you would have almost no shot at, just because you had to understand HOW you were supposed to interpret/see the test item.
The ACT, she definitely felt was less of a "prepping" fest.
The ACT was a matter of MUCH more significant pressure on reading speed, though. DD liked that-- it was much more like the AP test format. Less down time for DD, but she enjoyed it much more because she was able to get in the zone and stay there for longer.
Most students never even finish the sections in the ACT. DD had little time left OVER in the Science section, but the rest, she definitely had lots of time. Strategy-wise, she used that time in the math section to immediately begin working her way BACK through the test items until she ran out of time-- that meant that for the last 2/3rd of the section, she worked the problems twice. The other two sections, she worked them through at her ideal pace and then just waited.
