AnandTech: Apple Makes the Switch: iMac G5 vs. iMac Intel Duo. Well, it might seem like a no brainer to get the new iMac, but a couple of great points this article makes:
* The Intel Duo is an interim chip for the desktop Macs. There is a new chip "Merom which is the desktop version so putting them into iMacs is just to get them out. The chips are pin compatible, so presumably the MacBook is going to be longer term and shortly in 2H06, the desktops will get much faster.
* Apple has ported their core applications, but not their professional ones. Microsoft and Adobe have announced but haven't shipped their applications, so most of the time you are running in binary translation mode which means sloooooww.
* The industrial design of the iMac is amazing. it is only 1.5 inches thick and with a bluetooth keyboard and mouse looks incredible.
* If you buy one, then upgrade right away, it uses notebook Ram so there is another 200-pin DDR2 SO-DIMM slot (this is standard notebook memory), slam another 512MB right away to really improve performance.
* It uses a standard 3.5" drive, so you can upgrade that to anything you want. Comes with 160GB standard.
* Having dual core doesn't seem to improve responsiveness very much. This is unlike Windows which gets much better with a dual core system.
* Performance compared with a 1.9Ghz G5 vs. a 1.8GHz Intel Duo isn't a blow out. The 1.8GHz Duo is 30% faster on a few native tasks like video encoding, but for things like Keynote (their version of PowerPoint), it is more like 10%. So don't expect an amazingly 4x faster Macintosh as suggested by the hype. This just shows that the overall system is what matters and that since Apple has switched over to mainly PC parts (standard drives, memory, video) it is going to have similar performance.
* Running PowerPC applications is just terrible. Applications double in memory size and they get 50% slower if they don't crash.
As a final caveat, these applications aren't tuned and use the gcc compiler, not the Intel tuned compiler, so while the new Macintoshes are exciting, they aren't the true revolution. Longer term though, they are going to be more mainstream as they use a high volume chipset and then there are the ergonomics of the OSX. It puts things on a more level playing field.