Hi
Personally, I would drive for an experienced tester. We tested DS12 on WISC-IV after DYS level results on ACT. It really was helpful on a personal level to understand him better. He did test above the DYS criteria on WISC-IV and I came to really understand how my idea of "normal" is really off. He seemed pretty normal to me.
The schools may or may not embrace the information. We actually found ACT scores had a bigger impact on the willingness to do more for our DS. The schools are familiar with the test. If your 12 year old is out performing their seniors it is meaningful information.
I would make sure any tester you choose would use extended norms and GAI. If you have any 2E concerns that experience is also important to know about the tester. Our tester would not calculate extended norms for our DS even though he met the criteria by a long shot. I didn't think to ask before hand because it never occurred to his scores would be that high. Our DS has scores that has hit a ceiling but ultimately we don't know exactly how high it would go with extended norms.
I was really glad we tested and it put a stop to me second guessing my perception of his ability.
Good Luck
