I recently purchased my second Sport dog collar set up over the past 5 years. I am extremely satisfied with their products and their customer service is over the top. I once had a collar comeoff(my fault) I called them sent me a new one for $10. Recently on the new set up, a Pro Hunter 2500, I lost the transmitter (no I am not an idiot, though it sounds like it). When I received it, the transmitter did not have a lanyard set up my preferred method of carry. I called, they advised that the only thing available was a belt holder. So I built my own lanyard (dumb idea) and lost the transmitter. I called them advised them of my displeasure with the carry methods offered and the fact that I lost it. They were willing to replace the transmitter at no cost. No wanting the same issues I asked about changing to a different model, No problem no cost new transmitter. All of their collars are interchangeable.
I posted this earlier when guys were talking about tritronics, I personally wouldn't own anything else. I have since recovered my 2500 transmitter so I am even in better shape.