Normally experts recommend 1 test / week because you need to do a post-exam analysis and from analysis, you should see where your weaknesses are and try to fix those weaknesses within a week and take a test again. That is the whole idea of taking 1 test /week.

I agree. The practice tests are only useful for two things: giving you the stamina to sit and take a full-length exam, which really isn't a huge struggle on a test the length of the GMAT, and providing you with the tools to examine your own strengths and weaknesses through the questions. In order to really benefit from a practice test, you need to sit down afterward and review every single question, including the ones you got right. Particularly in verbal, understanding why each of the wrong answers is wrong can be a huge advantage, and if you got a question right because you got lucky, not because you actually understood it, the only way to find out and correct potential problems is to review. I honestly can't stress enough the importance of review, and as a tutor, I am often frustrated by the emphasis that students put on taking practice tests and then focusing just on the score, instead of on the questions themselves. One test a week should be sufficient, with the balance of your study time spent focusing on content issues.

I am planning to take the exam next Tuesday. I was thinking of taking two more practice exams - one tomorrow (Tuesday) and one Friday. I have already taken 11 practice exams...is this excessive? Will this just tire me out for next Tuesday? Any thoughts?

Thanks!