What is the point in asking these questions now?
Any hardware should be 100% stable on its own, it's the operating system and software that is the question!
It's a bit like saying "how stable/fast are PCs?" then judging it by using a buggy beta of Win95 as the software you're going to test it with...
In case anyone on this thread doesn't realise, the AmigaOnes are running PPC Linux, not any release of AmigaOS.
The only worthwhile questions are about AmigaOS4. What are its minimum specs? How well does it run on those quoted minimum specs? How stable is it? How responsive is it? How quickly does it boot? etc.
(NB: there shouldn't be ANY data corruption/stability issues under heavy load! I don't know what people have come to expect from their computers these days...)