It really depends on what you're trying to do. Tbol is going to be better for a cycle that one is looking for less bloat and more clean gains, dbol would be better for more of an offseason bulk. Also price comes into play. Tbol is more expensive then dbol so one would need to weigh that out as well.
Now it's also important to note that dbol can absolutely be used while dieting down or in a cycle for lean gains, ones diet just needs to be adjusted accordingly. Arnold would always run dbol into his show and he looked phenomenal.
That's my two cents