Well the price. I dont think its worth the extra money for the 65w versions. IMO I would stray away from both of those cpus and get a X3 720 or 710. 6mb of cache and faster ghz. You get one less core but most games dont take full advantage of 4 cores anyways.
I know what the TDP is of the cpus I listed. They are just as easy to cool as the 65w version. You take the stock cooler and slap it on. Thats it. By the way the 810 the OP is considering is rated 95w part as well. So what does it matter that the cpus I have suggested have a 95w rating?
I'll say it again. Its pointless IMO to pay more for the 65w version. I just built a machine with the 710 and it runs very cool, just a little bit warmer then room temp(Case doesnt even have a intake fan installed). My buddy is using the 720 in htpc with similar results.
It is no stress experience to cool these cpus at stock or with a overclock.
The 905e is just a chip that binned well enough to run undervolted. The 905e would not be any easier to cool than my 940BE @ same clock speeds and voltages. Those chips are more designed for HTPC use than gaming. Save yourself some money and buy a 95w chip. Though I would get a 95w Ph II 945 over that 810. 3.0ghz and more cache over the 810.
yeah dude, id recommend a 720!! great to overclock low voltage, and if your mobo allows it you can unlock the 4th core of it, think for the price £80, it is probably the best cpu on the market, as far as price to performance goes