Not sure which version of the I4 yours had, but its going to be about the same. There isnt that much of a HP difference between the 2 models. I had a gen 5 I4 before the 2012 and I didn't notice much of a difference between the 2. For a daily driver, the I4 is fine. I probably would have went with the I4 again, there is nothing wrong with the it, but I wanted something with more power so I bought the V6. The car flys with v6, I have caught myself doing 65-70 on streets at times without even noticing it. I have no complaints on it, I've put about 2.5k highway miles on it so far and its great, plently of passing power, up hill power. Since I bought mine, I have only see 2 other v6's and the dealers around here only have only would have a couple if any.
If you do mostly city driving, go with the I4, you will get better gas mileage. I get around 15-18mpg in the city. If you do a even mix of city/freeway, I would get the I4 If you do mostly freeway, its up to you.