Been a Tile user from the early days when they had sealed units and planned to make money off annual replacements. I have four of the Tile Mate with replaceable batteries. At one time I had two of the Tile Slim (card), but those have sealed batteries and I just couldn't bring myself to replace them annually at that cost. I've also long since combined my phone and wallet with Apple's surprisingly durable leather folio case, which means built-in support for Find My on my wallet.
My primary frustration with Tile right now is the need for an app that constantly uses a bit of battery power: 6% over the last 24 hours, multiplied out over a million phones, that is a significant energy consumption. Early on, Tile app would use up too many Bluetooth connections, resulting in dropped calls with my AirPods. Tile eventually added a "Limit Bluetooth Connections" feature to address this. I notice now, that is gone, so maybe it has been solved in another way.
If I could make a change to Tile, it would be that when I disable the "Find iPhone" feature so pressing the button on the Tile doesn't make my phone go nuts, is that it should likewise no longer make the Tile go nuts with beeping.
Aside from those two items, I have a background concern about Tile's respect for my privacy... which "free" analytic frameworks do they use, if any? Is my usage data being sent to someone like facebook or some data aggregator? Unlike AirTags, Tiles have static Bluetooth MAC Addresses, so that means they can be tracked from store to store just like phones used to be.
I'd like to try AirTag, so may order one. The lack of Family Sharing is a bit of a deal breaker, though. I hope that is resolved soon. Even better would be for Apple and Google to agree on a cross-platform standard, like they did with the Exposure Notifications, which uses a similar architecture as the Find My network.