I am in the market to purchase some additional AirTags. I have been using four 1st generation AirTags for a couple of years and have been generally pleased with them. However, I am considering purchasing Ugreen trackers instead as they are substantially less expensive than AirTags. Any opinions on which you think I should purchase? I might need more than 4 so I am thinking about hedging my bets and getting both. Also, for those of you who are using 2nd generation AirTags, what is your opinion on them? Please share your thoughts. 
I’d only use a tracker with ultra wide band in it (what lets an Airtag arrow point within sub-inch precision in real time as you move.) I don’t believe UGREEN offers this. UWB is nice if you have trouble finding things in your house or if you want to be able to pinpoint something on a lost-and-found counter. It doesn’t matter for longer distance tracking (did I leave the iPad at home or is it somewhere in my baggage.)
I have a set of Ugreen, bought them because of the price. Works really well, updates quick and is always online. The beeping is enough for me to locate them when I just displace something “locally”.
To be transparent I have never tried normal Airtags, so I might not know what I am missing. 
If you need accessories, AirTags probably has the largest variety available.
I purchased 2nd Gen AirTags to use with the Elevation Lab AA battery pack which lives in the trunk of my car.