I looked at the same cars and of course decided on the IS. For me there were several reasons. I believe Lexus will offer the best quality and after purchase service. All the quality surveys would suggest this to be the case. I much preferred the styling both inside and out of the IS over the others. I found the interior of the 3 series in particular to be very underwhelming. I didn't like the plastics and the overall shape of the dash in the BMW. In terms of the power and price, yes the Infiniti wins for the price, Lexus and the Infiniti are similar for power. The 328 is way down on power in comparison to both of the others. I just found that after driving them all it was the Lexus that I lusted after, even with the higher price than the Infiniti.