Ive been using one for ages.
No problems at all.
The machine wakes up same time as me and by the time I shower and dress its ready to make my morning cuppa.
In fact, Ive noticed that the switch on my Expobar appears to be a little damaged and it cant be from turning it on/off because it stays on and the timer does all the work.
If Id have been manually turning the machine on and off the switch would have been completely broken by now.