we got a Tractive subscription for one of our cats when he went on a 5-day bender a few months ago. He has the new gen collar, the one that's built in and not as bulky. I was surprised that he didn't object too much to wearing it, as normal reflective collars absolutely terrified him.
The first time he got it off was about three days in.
The collar has a safety release if they get stuck on a branch or something (this is VITAL, you don't want your cat to strangle) and very detailed instructions about how tight to have it, and you can set a slider in the buckle to four separate weight settings for your cat, which means that a larger stronger cat has the buckle set to a firmer grip. We don't want our cat to hang himself so it's set to 'Medium'.
I've lost count of how many times he's dropped his collar in the three months he's had it. Only once or maybe twice has it looked like he actually got it caught on something. The rest of the time I think he's worked out how to scratch his collar really hard in the right direction and the sodding thing releases! So while it's been really very easy to track him down at the end of a long day out and pick him out of a field/hedge/someone's garden (he is MOST unimpressed that we suddenly have the ability to know where he is. I tell him we're magic now) if he sheds the bloody thing you just have to rely on him coming in of his own volition. Mostly he does but right now he's been gone two nights.
Obviously, once the collar comes off, you can track it down with your phone, though once you get in range it might still be a bit of an effort because of the GPS going wonky. At night's the easiest to find it - you can activate a light which isn't very bright but enough, and it'll also play an extremely quiet tune - think tiny elves breathing lightly into a recorder - which may help if it's not windy or noisy. If you lose it in your 'power saving zone' (which is a radius around your internet hub) then you have to go onto 'radar setting' to find it which is really irritating and frustrating to use. We think it's a bit like geocaching but with fewer rewards.
In terms of how accurate it is - not always very! I think GPS is subject to local conditions and undergrowth, which in this rural area doesn't always help, but sometimes I've seen on his trail map where it looks like he's crossed right over the river! (There is no bridge) But it'll help you get an idea of his range - which may freak you out.