I have had the Weber remote digital Thermometer for 2 years and use it on average 1 1/2 times per week. I swear by it. However most of the other brands that you have in the USA are not redily available here in Australia so i can't compare it with anything else.
Weber had a problem with the wires, where they come out of the probe, shorting out, the reading would go to 199 C. Thier customer service would replace the probes no problem but it was annoying to those that had the dicky ones.
They appear to have fixed the problem now.
Bottom line - whatever the brand a remote probe takes the guess work out and ensures that everything is cooked perfectly.
My Brother-in-law bought one of the weber wireless probes at Target, mistakingly thinking it was the same one that I use (I use a Maverick ET-7)
He fried his probes within a day of using it. Countless reviewers on amazon blast the thing for frying probes too easily and generally being a POS. (Maybe they used to be good, but switched manufacturers?)
YMMV, but from what I've heard there is a high defect rate on them.
Other probes - like the Maverick - can be had for similar price if you buy them online. I've never fried a maverick probe, but if I ever do - (my unit has two probes) I can just mail them my fried probe and they will mail me back a new one.
If you do get one and it works well, let me know - They are readily available and pretty cheap ($30). I wouldn't mind picking one up when I find myself 500 miles away from my grilling stuff and asked to cook a turkey for Christmas dinner (That happened to me this year... you never know how much you love your grill accessories until you are put in front of a grill without them)