Short take: USDC = stronger transparency/compliance; USDT = deeper liquidity/more pairs. "Cheapest" depends on chain/venue (Solana & L2s usually low fee; ETH mainnet can spike).

Pick by use case
   •   CEX trading: USDT often tighter spreads + more pairs.
   •   DeFi/payments: USDC is the default quote on many apps and cleaner for bookkeeping.
   •   Multichain: Prefer native mints; be cautious with bridged/wrapped versions.

Risks (both): centralized issuer, potential blacklisting, depeg wobbles under stress. Compare gas, withdrawal fees, and slippage—that's your real cost.

Your data point (copy/paste):
[UTC time] Venue/Chain:
Use case: (CEX spot/perps/DeFi)
Fee & slippage observed:
Any peg wobble/notes:
My take: I hold both - USDC for DeFi/accounting, USDT for trading depth. What's your default in 2025, and why?