I thought that the bio was on par in both cases if you do enough practice passages. I got a 10 in the bio section and that's about what I was averaging on TPR tests.
I think the science workbook passages were pretty good and that the bio was actually a lot of interpretation of data in the real deal. The one thing that some of the TPR passages was not good for was that it had a bit more straightforwardness in their bio passages but the real deal had a lot of data interpretation. That said the previous attempt at the MCAT had some questions that were the exact same things I'd seen in TPR but that was for the PS section. I think the AAMC tests are the best sample for getting a better idea but you should use the TPR tests for practice because more practice always helps.