I have tracker maxima receiver with wildlife collars. I don't use mine that much to know. I did a bit of research when I was looking at getting some and I was told the alloy collars can be damaged easier than the plastic cased collars, I haven't witnessed this but that was the main reason why I got wildlife collars. The plastic casing has held up really well and have cop some minor hits so I'm happy with their performance. A lot of people do say that some are easier to use than other brands but I think its how well a person can use it - like I said I don't use mine often enough to know. Also I have been told to use headphones with the tracker brand - I haven't done this as yet but the size is the thing I like - a lot of it is personal choice. I think the important thing to remember is that it is not a gps, it only gives you a direction on where your dog is. The only thing that I am not happy with the tracker maxima is that if you are not actively using it, after 3 minutes (I think) it will turn itself off and you can't change this setting, this can be a pain but I suppose its better than finding out you don't have any battery power left. Oh one other thing, make sure that when you do get one, carry it in a bum bag or a bag that is very secure as people have lost theirs after the stitching on the loop on the belt pouch has come undun. Good luck.