I can tell you that the U2 drop-in I got from Kaidomain was every bit as bright as the UF T6 from Manafont. See for yourself: https://budgetlightforum.com/t/-/2110
I liked the tint too and I paid a lot more than $10. If I remember right, U2s had not been available for very long . . . not sure.
U2bebrightFoy