I am of an opposite view, Ducay - I love my igrille Mini - I leave it in my steak and then I know exactly when to flip it and when it's a few degrees away from my desired cooked-ness (ie: 60C for Medium). alarm goes off 6C before it's ready (10F) and I go out kill the heat and let the grill's heat take'er the rest of the way up to 60C and it's always perfectly medium...
It makes it easy to lazily cook a steak on a gas bbq in bad weather especially.
In the nice weather I stand there with my beer and pretend I am working so I can stand on my deck
I agree it's a waste of money at $80 for a dual-probe + gas grille - but if you can get the igrille for $20-30 on sale, I find it handy.