Ethereum confirms fastest of the four and connects your activity most tightly. That combination catches people, because speed feels like an improvement and the linkage is invisible until somebody looks.
The account model
Bitcoin and Litecoin move discrete outputs, and a careful user can avoid reusing addresses. Ethereum works on accounts, where one address holds a balance and every transaction it ever makes hangs off the same identifier. That makes address reuse the default rather than a mistake, and it means an address used for an order is permanently tied to everything else that address ever did.
If you use an address that has interacted with an exchange withdrawal, a token, or any service that knows your name, that connection is now attached to this payment as well. Using a fresh address for the purpose is the minimum, and it is still a public record.
Timing and fees
Blocks land in seconds, so confirmations complete in five to ten minutes, which is the fastest of the four. Fees swing widely with network demand and can spike sharply, so check the current estimate rather than assuming.
Wallets and Tor
This is the awkward one. Most Ethereum wallets are browser extensions, and installing extensions into Tor Browser is a bad idea for reasons that have nothing to do with this market. Use a standalone wallet application rather than an extension, keep it separate from the browser you use to reach the market, and do not weaken the browser configuration to accommodate a wallet.
Honest position
Ethereum is here because Anubis accepts it and some people hold it. On privacy it is the weakest of the four, and choosing it should be a deliberate decision about coin you already have rather than a preference.
Verified addresses
anubisqdpukalgiyxlb7rtcya3u6grun2mcozonmb57c54qrt7sqh7qd.onionanubisqe2yramasw5yvlnipaknraza5rzb5uxb7zqhxuxroobvvm6aid.onionanubisqocgruji655mqys7fpafawiy2g56pjqrtecfdikhh5q4zqmfqd.onionBefore you sign in. Open these in Tor Browser only, then compare the onion printed on the login screen against your browser address bar. If they do not match, close the tab.