There is no i5 processor that is faster than the FX-8150 overall.
AMD FX-8150 @ 3.6GHz 8,162
Intel Core i5-3570k @ 3.40GHz 7,722
Intel Core i5-2500k @ 3.20GHz 6,719
The Tech report did an article titled "further overclocked" when they were able to attach AMD's closed loop solution and reported "turning up the clock frequency allows the FX-8150 to put up some really nice numbers, tying or beating a Core i7-2600K overclocked to 4.5GHz in several cases".
This is all on an unoptimized Windows 7 platform as well. If things were using the right instructions and optimized for bulldozer the benchmarking numbers would be looking much better for it. With the developer build of Win 8, the FX did, in fact, yield better numbers.
The i7-2600 has Hyper-Threading whereas the two i5's mentioned do not. My 2600 cannot keep up with my FX-8150 when it pertains to multitasking. Try playing BF3 while capturing the game with Fraps and encoding other video within a VM and see how well that 2600 does let alone the weaker i5. The FX-8150 is a multitasking powerhouse, albeit a power hungry one as previously mentioned.
To be honest I had no expectations going into the Bulldozer build. As a seller I knew if I wasn't happy I could simply sell the machine but would be forking out a lot more money in favor of the i7-3930k to do what I need. I was tired of having two PC's in my office when I knew with the right processor, I could do everything with one system. The FX-8150 made that happen and for much less money. In no way does the FX-8150 feel slow as a desktop and compare the prices at Newegg, you'll get far more bang for your buck building an FX-8150 system than you would a 2500k.