Not sure what you are comparing against or what you want to drive. Unless you only want to buy silvercore, just comparing those tubes or amps does not make sense.
The 833 is a good value amp at 20w if you are on a budget in the used market. There are many SET applications, you can get better 300b or 2a3 and other stuff at lower watts, you can get more if required in more powerful amps, but most of them are more expensive such as Kronzilla. Mayer, lamm, Kondo. No shortage of amps. I prefer a locally made GM70 to Silvercore’s 833, and it’s not expensive. There are also SETs made in Vietnam and Japan. Silvercore himself has made a 212 and an Eimac 304TL (80w class A) which was better