I just finished the GRE. Like others, reading through this thread helped to reassure me when I was studying and so I'd like to share my scores as well.
So I actually only took three practice tests in full. In chronological order:
PowerPrep 1: 159 Verbal 169 Quant***
Manhattan 1: 165 Verbal 159 Quant
Manhattan 2: n/a 166 Quant
Manhattan 3: 163 Verbal 162 Quant (about a week before the actual exam)
Actual: 167 Verbal 167 Quant
***The169 Quant score that I got on Powerprep 1 was aberrant; I just got really lucky with guessing. I took this test about two months into my studying and I was certainly not at a 169 level of math understanding at that time.
I wouldn't necessarily call the practice tests any easier or harder than I saw on the day. The Manhattan test vocabulary is certainly more obscure than what I saw on the test though - I think Magoosh practice was better for that.