I have a friend who took her daughter there. I think she was at her wit's end with her daughter's ADHD and it is said that sometimes learning issues have ways of displaying symptoms similar to behavioral issues.
The testing is "cheap" but the services--

Crazy expensive.
She only sent her daughter b/c her parents covered the bill. (they were hit hard by the economy and lost their house--so it certainly was not a service they could afford).
I think we're talking like $2000-$3000.
And this is for something like 12 weeks of classes that actually do some very therepeutic things. (no idea what, but from what I have seen their can be vision therapy and some balance therapy and some other things--but I do not know the details. I do know that the services are specific to what came up on your child's assessment.)
The result?
She raves about this program and found it very beneficial for her daughter.
If I had the money, I would consider it for my oldest daughter. But I don't. So we just manage without it.
I wouldn't bother with the testing if you don't anticipate being able to do the services.
It's their own tests and likely they may not let you take the results (though I do not now for sure).
Another option--my son's Speech therapist had some type of program as well. I can't say it was similar to learning RX, but it was supposed to be helpful for certain behavioral/learning issues. It was pricey--but much cheaper than learning RX.
So you might check around for other learning centers or other places like a speech pathologist who have any type of learning diagnostic test as they may have cheaper services that you can take advantage of so that your child can have their weakness addressed and fixed.
My speech therapist offered the program over the summer.