Considering Intel Core i3's can handle BF3 multiplayer just fine, I am not too concerned about the FX-41XX/43XX.
However, I would highly recommend the FX-4300. It will perform better than the FX-4170 due to the refined architecture while leaving you with a massive OC headroom for even more performance. Of course, if you would like to go Intel, the Intel Core i3 3220 is a GREAT value as well. You will have a significantly larger upgrade path with an i3 than with a FX chip.
Between the two, i vote for the FX 4300....the improved IPC of PD should enable it to match the slighlty higher clocked FX-4170, but at the same time using significantly less power, only 95W vs the 125W of the older 4170.
In other words, it also translates to lesser heat while OC'ing