Hi, not sure if this will be of any use to someone but i was in a great position to compare new and old - I sold my PowerMac 2.3Ghz Dual Proc system to get a new Dual-Core 2.3 for PCIexpress as well as other things. Both have the same amount of RAM too (1.5GB) but the newer system has a Geforce 6600 and the old system had a 6800GT (the only thing that hurts it). Well i just thought id post some observations so far.... I can't take any pics sorry, they ran out of stock of the iSight cam i wanted so i didnt get it. Quick Run Down: The new 2.3 is a lot quieter than the last. I'm sorry to say that the 2.3 when it was turned on, and when starting a GAME or other CPU intensive task the fans would spin upto full speed and then sort of throttle back a little and level off. It was really quite loud. The new design for cooling seems a lot better, at full throttle its still pretty silent. You can only tell its speeding up by the slight change in pitch/tone of the fans. They are obviously either running a lot slower max, or are better designed for noise reduction. I noticed a type of rubber seal around the side panel. I don't remember seeing that at all before on my last PM. Its either there for noise, airflow (or both?) or some other reason. There is still a plastic 'form' after you remove the metal side panel (to still direct airflow) but i noticed the fans directley behind it for the CPU dont quite cover the entire width of the case. There is a small gap to the side with what looks like a funnel/vent. I also noted the sticker about liquid cooling leaks on the inside of the case -- its either a generic warning or the new systems have heatpipes? The logic board has heatsinks allover it. There are two between the 8 RAM slots, and a rather large one where the PCIexpress slots are located. Speaking of which, the PCIexpress are laid out as 4x,8x,4x and 16x. With the 16x so being right at the bottom. Same large space for big cards (and support at the back). The Hard Drive bays seem unchanged, but they seem to be using Western Digital drives now instead of the Maxtor i got with my original one. This is a big improvement because the maxtor drive did make quite a bit of noise when accessing -- WD is a lot less noticable. Graphics Card has passive cooling. Large heatsink that seems to cover the memory as well as the GPU. Early indications point that its obviously no 6800 but it does an admerable job. Can play WoW at 1680x1050 still. However i still cant wait for the 7800GT to arrive so i can turn up the shader options once more System responsivness seems about the same, but then i never expected there to be a HUGE performance increase (or any). Apple have done something with the PowerSupply i noticed. Not sure what, but when flicking the power on to the plug (its turned off at the wall usually) there is definatley an audiable 'click' or thump coming from the Mac's PSU. Bit like its 'waking up'. The one on the old 2.3 never really did this. I have also noticed the big red light at the back (near the power button - but inside the case) - I don't remember seeing that before but its possible it was there on the last one and i didnt notice. Finally, a small change seems to be the Mac Startup sound, if you hook external speakers upto the system the startup sound still plays through the macs internal speaker - not the external speakers like it used too. Hopefully that has been of some use to someone. Ill add more info if i find anything else out.