new cpu card with gfx card, ide controller and Ram so for what the A1200 is needed ?
I can think of joystick, mouse, sound, psu.
The original chipset? That way you get the best of both worlds. A PowerPC CPU faster than the Blizzard, without a 68k for context switching nightmares, and access to the original chipset to run some software that would require E-UAE on the A1.
On the other hand, old Amigas are dying... The A1 is more of a future investment.
So... something for everybody ;-)