Hi
Not a bad idea if your not overly concerned about sound, it is cheaper than a sound chip.
Drawbacks would be, doesn't sound great, you would have to put a wagon or coach with all your engines to have sound, it's on all the time and to switch it off you would have to open the unit its in n pop the battery, all your engines types would sound the same, its motion detection response is slow, you cant change the sounds....
I would save the money one would spend on this, add to it, and buy a DCC sound chip. I think its worth it in the long run...
Eoin