The Intel core i5 3570 CPU is a very fast and efficient processor. The reason I bought this instead of the Intel Haswell series is due to the high cost. The Intel core i5 4670 (the Haswell CPU that I would have bought) was priced around £200 at the time. There wasn't too much of a performance difference to deem it worth the extra £50. Now, I think that the Intel core i5 4670 in the one to get as it is cheaper than it was. This means that the added performance that the 4670 gives is now worth the tiny bit of extra money, because it is cheaper.
After a few benchmarks and four months of use with this CPU, I can honestly say that for the price, it will be quite difficult to find something better at this price point. It is a very reliable CPU and has very good technologies built in, in order to make the experience of using it better. Things like hyper-threading and the Z77 chip-set that is embedded in my motherboard makes this CPU faster and more efficient than a normal quad core CPU, with a base clock of 3.4 gigahertz like the AMD Athlon 750k.
These technologies also help it to be energy efficient, for example the Intel core i5 3570 has a maximum wattage of 77, where as a normal quad core 3.4 gigahertz CPU, like the AMD Athlon 750k uses a maximum wattage of 100. The only problem that people have had with this CPU, which I do not encounter, is the integrated GPU inside the processor isn't very good, however it probably isn't noticeable if you aren't doing anything graphically intensive, or you are putting in a separate dedicated GPU.