Anyone have experience with Halo or Spot on collars ?

As an anti aversive forum, our feedback is not to use this sort of device.

Please read the reasons why here - Invisible Fence, electric fences

Should you wish to find out how a dog feels, buy a shock collar locally (that is returnable); put it around your wrist, and trigger it. Trust me, you will not like the pain!

I like your thinking, but like my dogs too.
When I first installed an underground fence I got the one with 3 types of corrections.
Since I was doing it my way and not yours and my dog was an extra large Newfoundland I didn’t go the finger route. I went first and the collar fit around my large neck. Since I did not enjoy the static mode I trained her with the painless beep followed by an equally painless vibration.
Both Halo and Spot On have similar settings.
Don’t be so quick to judge before you know more.

We would still say these are aversive, and I hope you did look at the thread I linked; they can result in tragic consequences.

Why not consider a conventional fence?

I understand that an "invisible" fence sounds like the perfect solution, but as the story in the link by the moderator sadly illustrates, there are things that are too tempting for a dog. There is also the issue of getting shocked or beeped or whatever upon going through the "fence" and not desiring to return due to the undesirable consequences experienced. Please put up a real fence or take the dog out on a leash at all times. This my humble opinion.

An electronic collar might stop the dog from leaving the property, but it doesn't protect the dog from things entering the property. In my yard putting a dog out wearing an electronic collar is basically just staking it out for the coyotes. We have a fence to protect our dogs.