A PC with those sort of specs would be horrible.
You cant really compare an 800Mhz x86 to 800Mhz Motorola architecture as they are radically different. Clockspeed isnt a good guide to how fast a computer runs. For example, back "in the day", the amiga (also motorola 68x 7.1 Mhz) was generally outperforming PCs with the 386SX (intel x86 16-33mhz) on half or prehaps even as much as a quarter of the clockspeed.
B.O.T.
Im after an new and old mac too for compiling stuff on that platform :/