Garmin astro.with the D.C. 30 collar is the best I've have found, Use one and you will trow the 'old school' units in the creek! Use mine bout 4 times a week and love it. If you have any questions about gps fill free to ask. always happy to help.
I've got several friends with them also... but there "old school" collars are still around the dog's neck for insurance. It comes in handy and is neat to watch, but it doesn't have the range for me to feel comfortable in turning out a dog with only the gps collar.
