Bests & Worsts Reviews from Amazon

So far I'm giving this two stars because I haven't been driven to outright "hate" it.........yet, but I definitely am very frustrated with it and "don't like it". We already have a PetSafe unit model #100 which is the old version of the now 300. It was easy to set the flags for that unit, with consistent reproducible results when testing it. However this model has consistently rendered *inconsistent* results when testing flag placement. So I finally called the manufacturer. I give their customer service 5 stars. They are very available and helpful. Apparently there's a specification for use of this model that they fail to mention in the write-up. I was told by the rep that this particular model emits a "dome-shaped" signal field, which essentially means that it can't be used where the area it will be used is sloped. The rep said that sloped areas seem to cause the signal to be unstable, so the collar could end up beeping (and shocking) *anywhere* within 10 feet of it. My dog was getting fully well past the flags but getting shocked (with no beep warning) on the way back. Horrible! The other model 100 (aka 300) emits a ball shaped field, so it can handle sloped areas and offers a more stable signal under these conditions. At present I'm extremely frustrated with this item and am considering returning it.