Hello, I emailed a well regarded German dealer about storage in his build-to-order Mac Pros. He told me to avoid 3TB and 4TB hard drives in the spare bays as they tended to render the machine unstable. I asked if it was a generic problem with the 2008-2012 model [other Mac sellers I've spoken to tell me they've never heard of it] or simply the result of the modifications he makes. He didn’t elaborate but it makes sense to think he’d blame the machine’s limitations rather than his own. I'd like to clarify this question if possible. It put me off buying initially but I'm quite keen to depending on the explanation. He said: “….we don't recommend to install 3TB and 4TB drives. You can not even deactive [sic] or format these drives. You should use 2TB drives max.” This too: “3TB and 4TB can be installed in the machine but it's not recommended cause they are not 100% compatible. For example it's not possible to erase these discs using the disc utility. We don't like to install to these drives but we can do it anyway if you insist.” I’ve seen a similar thread on these boards but started a new one because this is the first direct advice from an experienced seller I’ve come across, and as much as I'm reassured to be told ‘trust us, we’ve been doing this a long time’ I just don’t know whether to take his advice as I'm not very computer savvy or experienced in these matters. Any thoughts?