Memory issues and sluggish response
"we found that the menu system on our review sample could sometimes be sluggish to react to button presses, taking a touch longer to respond than we’d expect, particularly if other applications were open. Occasionally, too, we experienced odd software glitches that suggested memory was full"
Doubt Motorola will sort as the Z8 has exactly the same problems. Also when your low on battery whatever you do, don't slide the handset open.