Toying with getting some, thought the lack of the U1 chip makes me thing £9 less than an AirTag 4 pack (or £2 more if you get an education discount) is making me think twice.
Though the fact you don’t need to buy a case as it has a hole in it no doubt saves a fair bit!
I ordered one to try it, unfortunately I missed their email so mine’s not coming until August! And I had to pay shipping for it. I plan to put it on my spare keys, hopefully it’ll work for that.
I wonder what import charges they will hit you with? 
Hopefully none, VAT is paid upfront and as it’s under 130 you don’t pay duty.
I ordered a 4 pack last week, there were no import charges.
They are bigger than I thought they might be.
Easy pairing and so far working fine.
Not as pretty as an airtag but for what I wanted (keys to out buildings etc.) they’re good, no need to buy extra cases.
Now fully removed all my tiles and deleted the tile app.
Also if you put them in your basket and start checkout but leave, you’ll get a 10% code emailed to you 
The one I ordered arrived a few weeks ago and it’s ok. It doesn’t have the same tracking in as an AirTag (no precise finding, just “beep, and get me map directions there” which isn’t anywhere near as good as the AirTags. As it’s so close price wise for just the device, I’m not sure it’s worth the tradeoffs? Though it is a lot louder.
With the 10% off I think I paid £81 for the 4 rather than £99 (plus cases) for the AirTags.
Does depend on the use case, I have airtags on things that leave the house (car keys, wallet, house keys etc.) whereas they keys etc. that I put the onespot on shouldn’t leave the house, I just have a habit of mislaying them and for that the saving is probably worth it