Yes, I have used Spot. It worked across Europe, central Asia, the Russian far east, USA/Canada and North Atlantic (as advertised in their coverage maps).
The advantages of a 406 MHz PLB is that is is connected directly to international SAR, it works anywhere on the planet, sometimes the authorities insist you have one and it provides terminal guidance for SAR, often the most difficult bit.
Spot needs to be put somewhere where it sees the sky, something that you will forget and leave behind as your aircraft sinks underneath you. Though your daughter will shortly know you are in trouble.
I suppose both are a good idea.
I usually have as PLB attached to me when flying over sea/difficult terrain.