I've used one in competition for several months. The only problem we've had is probe failure from the pit door (apparently). We've added a fitting in the side of the smoker for the probes and we haven't had a failure since.
I just purchased 2 of the Maverick ET732 wireless thermometers and they are doing great. They cost less than an iGrill and I don't have to fool with using my iPad or iPhone. You do give up the graph function that the iGrill provides.
Bill Wheeler - Cleveland TN
competition team member: Jack's Old South & Myron Mixon Smokers.com
Southern Q Model 500 Water Smoker
Jacks Old South Original Patio Smoker
Jambo - FEC100 - Bradley Smoker - Nfusion