だけのことはある: effort that proved worthwhile
Evaluate a result as worth the effort already invested, and compare it with だけあって for an expected quality.
The effort was not wasted
この料理は、一時間並んだだけのことはあります。 means that this dish was worth waiting in line for an hour. It links the effort of waiting with the good experience afterward and judges the effort worthwhile.
The sentence does more than report a one-hour wait. だけのことはある adds the judgment that, in light of the result, the time or effort was not wasted.
Separate completed effort from the time of evaluation
苦労して調べただけのことはあります。 means that the painstaking research was worth the effort. 調べた refers to research already carried out, while あります can express a current recognition of its value.
苦労して調べただけのことはありました can look back on that evaluation in the past. Read the earlier た-form and the sentence-final tense separately so that completed effort does not become confused with a present or past evaluation.
Compare だけあって
経験が長いだけあって、説明が上手です。 means that the person explains things well, as expected from extensive experience. だけあって connects a background fact with an expected quality; だけのことはある can close a sentence with an evaluation of worth.
Do not read 一時間並んだだけのことはある as an instruction to wait for an hour from now on. The waiting is effort already made, and the point is to evaluate it as worthwhile, not to issue an instruction or obligation.
Is 苦労して調べただけのことはあります。 an instruction to investigate, or an evaluation of the effort spent investigating?
Show the answer and why
It evaluates effort already spent. It acknowledges that the painstaking research was worthwhile, rather than instructing someone to begin investigating.