Translation help please!

[AmayaIkuta]

Can someone please translate this sentence for me?

あれだけ意見できのはスゴイ。

Particularly, what do あれだけ and できの mean?

Thank you for your help! ^.^

[Javizy]

あれだけ
That much / to that extent. あれ suggests they're speaking about something that happened before that they both have knowledge of.

できの
I think this should be できるの.

あれだけ意見できるのはスゴイ。
That he can give an opinion to that extent is amazing.
It's amazing that he can express himself so well.

[AmayaIkuta]

あれだけ
That much / to that extent. あれ suggests they're speaking about something that happened before that they both have knowledge of.

できの
I think this should be できるの.

あれだけ意見できるのはスゴイ。
That he can give an opinion to that extent is amazing.
It's amazing that he can express himself so well.

Thank you so much! I really appreciate the wonderful answer! XD