Check the chain first
USDT exists on many chains; top-up fees and speed depend on which ones a card supports. A mismatch can mean expensive bridging before you even spend.
Then the fees
Compare top-up fee, FX markup on foreign spend, and ATM fee. For local spend FX matters less; for travel it dominates.
Finally, availability
A USDT card is only useful if it works in your country. Start from the best-USDT-cards ranking and your country page.