The Arctic seems to be a decent upgrade from a stock cooler, lowering temps about 15°C. Has no ram issues and at 150mm will fit in most smaller atx towers. Very good coolerfor the price, but will suffer on the higher wattage of the FX, especially under OC. The 212 is a great budget cooler, pretty much the standard other budget coolers are compared against, but it does have 1 issue , it's size. It won't work in smaller atx towers. At 160mm tall, it's the same dimension as a noctua nh-d14 which surpasses it in every way by a wide margin. The H7 is the superior cooler by a good way. The offset design puts it at 145mm tall with the same 120mm size fan as the 212. It also means ram is not an issue as the fan sits besides the ram, not over it. It's also a more efficient design heatsink with a better designed fan, so outperforms the 212 in thermal properties as well as audible volume.
Honestly, for an oc 8350, the H7 is the smallest cooler as I'd use, preferring the noctua, phanteks twin towers or a h80i or better liquid cooler.