Is there any difference between 「精々」 and 「たかだか」?


Like mentioned in the title, I would like to know if there are any subtle
differences between 「精々」 and 「たかだか」.

As an example, are all these sentences grammatically correct? Is there any
change in nuance?

> 出席者は **せいぜい** ３０人程度だ。  
>  出席者は **たかだか** ３０人程度だ。  
>  There will be about 30 attendants **at best**.
>
> 電車で行っても **たかだか** 一時間ぐらいだ。  
>  電車で行っても **せいぜい** 一時間ぐらいだ。  
>  If you take the train it should take about one hour **at most**.

