In your opening post, you stated that you didn't want to overclock. The 3570 is an overclocking cpu. It is, however a better performing cpu in terms of power consumption, newer technologies, and an increased CPU multiplier.
If you did add a 3570, then you would need an aftermarket heatsink fan and settle (if that's possible) with a 7850.
Similar to what I stated in a similar thread, if I had 700 to spend on a PC upgrade, I'd DEFINITELY get the Ivy 3570.
Alright thanks. So for what I do, is there any downside to getting the 3450?
The only downsides are no overclocking (limited unlock requires turning off cores, not very useful) and lower base multiplier. Since the 3450 should be more than fast enough for what you want to use it for and you do not wish to overclock, neither of these would affect you.
Interestingly enough, all the i5-34xx are listed at $174 on Intel's price list so my first choice would be a 3470S: 65W TDP (12W less than regular versions) with the same Turbo as the regular 3470, just need a good enough HSF (thinking 212+ or EVO) to keep the core cool enough for unlimited Turbo.