An A1200 is very reliable...until you start adding bits it was never meant to have just to get it usable for this day and age. Tower, keyboard interface kludge, buffered IDE interface, clockport sound card, PCI busboard...
By the time its as operational as the A4000 it'll be like the Frankenstein monster, with bits precariously hanging off at all angles. Before you know it you'll have the tower case permenantly off so you can twiddle with the stuff just to get your A1200 to boot properly each morning.
That's not to say A4000s won't give you trouble: they're getting on a bit and most users go through the regular routine of "which zorro card isn't being detected today".
But compared to the A1200, this is nothing. Turning an A1200 into something as expandable as a basic A400 takes a lot of time, a lot of skill, a lot of effort, and a lot of money.
