code9200Depends on what type of sound signature you’re into....
If you want a warm, laid back and “spongey tubey “ tone the WA3. My personal preference.
If you like a dynamic, quicker and more accurate type of tone, that’s more on the solid state sounding side of things, the WA6.
GOOD NOS tubes will also play a huge role in fine tuning the amp to your “likes”.
You asked which one is best....There is NO BEST. The “best“ one is what sounds “BEST” to “YOUR” ears.