I took forms 1, 2, and 3. I got a 234 on form 1 approx 6 weeks out, a 238 on Form 2 about 4 weeks out and a 258 on form 3 5 days prior to the exam. I got a 251 on the NBME's and they say that you should do within 10 points either way on the real thing if you read the bottom of the score report. It was true in my case and I think that 3 was the most representative although they are all different. I have the same exact strengths and weaknesses on all 3 so it will tell you where you are weak pretty accurately. Take all if you have time- it couldn't hurt.... Just my opinion.