First of all it should be placed directly on the mattress cover, and then cover it with 1 or 2 sheets. In this way he does not get dirty, and electrical son feel less (for me they do not bother me at all).
Then these are products that are made to work all night without a problem, there is also no time limiter. The disadvantage is that you think about it off in the morning, otherwise it continues to work for nothing!
It's quite slow to start, so you have to turn it on 30 minutes to 1 hour before bedtime. This is not really a drawback, just thinking about it.
The device-side engagement is quite large, but you can always manage to place it on the side of the bed, that way it does not interfere.
The switch is large, bright, pleasant, which allows to easily adjust the same night half asleep. Three graduations available, which is more than enough for my part I only use the last 2.
One last thing: to dry the sheets (or even the duvet) after sunrise, one can remain connected at maximum power for about thirty minutes.
In conclusion: a great product, very useful, at a very good price / quality ratio.