Which USDT network is best to buy?

Which network is most suitable for purchasing USDT? Could you please elaborate on the advantages and disadvantages of each network? Is there a specific network that offers better transaction speeds or lower fees? Also, does the choice of network depend on the country or region where I am located? Could you recommend a reliable platform or exchange for buying USDT on the preferred network? Furthermore, what security measures should I consider while making the purchase? Finally, how do I ensure that the USDT I purchase is genuine and not counterfeit? Thank you for your guidance in this matter.