Considering the 840 but have read a few reports (probably of the older generation computers - 530/830/1030) having the plastic mounting tabs break off.
How prevalent is that problem with the smaller 830/840 class devices? I would think we'd hear about it more if it was a regular occurrence. The only unit with metal tabs seems to be the much larger 1040 where I can see it making sense given the added torque it would put on a mount.
