10 or 25 ui/ml, which is better?

[WowOoo]

just trying to work out which of these is better..help!!

lower the better, so 10

If you're talking cheap Ebay tests then 25's. The 10's didn't give me a line until AF was due. The 25's worked 4 days before.
It's a quality thing rather than the units they supposedly can measure.

Thank you!