Current Athlon 64's are superior in EVERY WAY to Intel's. Yes the older chips used to not have a heat cut-off, but all of the recent ones do, and that includes all Athlon 64's. The Athlon 64's also run a lot cooler than equivalent Intel chips because they have much lower clock speeds. The main difference is the Pentium 4 and all of its offshoots are made for long pipelines (may have the wrong term here, but it means basically the same thing) and really high clock speeds, while the A64's are designed for short pipelines and lower clock speeds, this means the A64's have to send the information a far shorter distance and do not need the higher clockspeeds. The A64's are more powerful than the Intel equivalent and generally much cheaper, my A64 2.2ghz was about equal to a 600 dollar Intel chip and cost only 200. When I have it overclocked (cold weather only) it is capable of besting any Intel chip on the market when it came out, I go up to 2.4ghz.

That said you still have a solid cpu.

Congratulations on your upgrade!