Yes, I had one. I have trialled 3 GPS trackers, plus Tile and Airtag. This is because one of my cats went missing for 2 weeks, and once he was found I was terrified of losing him again!
Pawtrack had the best app experience (very well designed and easy to use), but I had to abandon it because the battery life was so poor. The first lot of batteries I received were duds and never charged properly at all. Then the second set they sent me as a replacement never lasted more than about 12 hours, which really defeated the purpose of tracking (it would probably take me that long to know he was missing!). Lastly, I had some serious concerns about the safety of it, because the tracker is built into the collar. The cat I bought it for is super active and the collar did not release easily at all.
I now use Tail it trackers on both my cats, the company is based in Norway I think. The battery life is very good, the longest Ive gone without charging is almost a week and it still had juice. The main downside is that you can't see a map of where they have been throughout the day, however realistically that's not actually so useful - cats are fast and can easily run a long way between tracking intervals if something spooks them. Tail It refreshes their location on demand, it also has a "live" tracking function which can be used as needed but this obviously burns through battery faster. The app experience isn't quite as slick but it's perfectly fine.
I have also trialled a cheap tracker from China which just ran off a SIM card without needing a subscription (I'm not in the UK), this was fine but the battery life was only about 48 hours. If you are in the Uk then you will have access to other brands as well which I don't.
Be aware that GPS tracking requires a line of sight to the sky to work - if your cat is locked in someone's garage or under a house or dense bush then it will be of little use. For that reason, my cats also have Apple Airtags, which I put in a special holder designed for a pet collar so it doesn't dangle (better for safety). Both the Airtag and Tail It are fairly lightweight, so it doesn't seem to bother them too much and I remove them at night (as they get locked inside when it's dark). I only attach them to collars which have a decent safety release - Boycat loses his every few weeks but between the GPS and Airtag I have always managed to find it again!
Hope that helps.