The G4 is a fantastic processor and, by all accounts, it's faster than equivalently clocked x86 CPU's from AMD and Intel. The G4's only problem is that it lags behind in clock speed -- just breaking 500 MHz I believe. Motorola can't seem to ramp it up to save their lives.
The Mac OS is the only good thing about the Mac. It's stable, elegant, easy to use, and simple to maintain -- years ahead of Windows in the areas that matter. But again, this advantage is dulled because operating systems have been stagnating since the release of Windows 95. Interfaces (at least the traditional 2D GUI with a mouse and a keyboard) have neared perfection and true multitasking is limitted only by the power of the machine. Operating systems are a dime a dozen these days, and since most people already know Windows 9x (and since it is relatively easy to get a free copy) and the Mac only offers slight advantages over it, there is very little reason to jump in with Apple.
Software is another issue. To have access to the huge array of titles available on the PC, Macs require a clunky SoftWindows interface that dramatically reduces performance. Sure, all the major software is readily attainable for Macs, but the same could be said for Linux or BeOS -- you don't see many people adopting those operating systems.
Another vital flaw of the Mac platform is its inability to stay current with the latest 3D video and sound hardware. This is actually a very important criteria, because the only justification for buying a fast, modern computer (other than professional graphics rendering) is 3D gaming. No other process is so demanding on computer hardware. Anything else can be done with a fraction of the power boasted by today's machines. So without modern 3D hardware, the Mac platform is crippled in the one area that makes a smart buyer consider a modern PC. And we cannot blame 3D hardware developers for not wanting to tailor their solutions to a small minority of the market.
The last, most important disadvantage of the Mac platform? Price. Take an average PC, say an A/700, 128M, 20G, GF256, 17", and compare it on a bang-for-buck basis with an equivalently-priced Mac. Enough said.
That is, unless you run Mac Photoshop filters all day.
Modus