I started with the cheapo Maverick and it worked just ok. Got a iGrill 2 last year and it's quite good if you have an iPad or iPhone. The transmitter can accommodate up to 4 probes, so you can do one in the flat, one in the point, one in the butt and a grate probe. The app shows you a graph of your temps along a timeline. (When did I last mop the butt? Oh, here I see that I last opened the lid at 3:54.)
I like it a lot for overnight cooks. I can wake up in the morning and check the graph and see just what the pit and meat temps at any time during the night. The key is to leave your iPad or iPhone plugged in overnight and the app open.
It is subject to the range of bluetooth, which will vary considerably due to placement of your pit and iPad. All in all, a good unit.