Hi, I had a pack of 5 Kaplan Tests. I had given 4 of them, and scored 324 in the first and 326 (164q 162v) in the last three. Scored a 326 on both my ETS mocks too. Yet, on the exam day, I was able to score only a 320 (162q 158v). I did not get flustered and gave it just the way I gave my mocks.

I decided to retake the GRE and after prepping gave the final Kaplan Mock and scored a 334 (167q 167v), a score that I'm satisfied with. Is there a trend that students tend to score lower on the main exam day? Do mocks scores generally translate into lower exam scores? I'm really confused and want to get that 334 in my exam too, can't risk taking the exam thrice! Any other free tests that you'd recommend?
PS I do have a few Princeton Tests as well, but have heard they are not up to the mark, and had given the Manhatton free test much before my prep.

Moreover, from what I've inferred from my friends' and my experience, is that the experimental section is always verbal. Is this a fact or just a coincidence?