word choice - Meaning of 「これはこれで」, and the difference between it and 「それはそれとして」

I came across the following lines.

・・・俺としては、下駄箱の中に手紙が入っているみたいなほうが好みだった。でもこれはこれで、少なくとも相手が積極的だってことはわかる。

I am wondering about the meaning of 「これはこれで」 here. As one might expect, it does not have any entries in the dictionaries that I use. However, it seems to me to mean something along the lines of "that aside".

If this is the case, what would be the difference between 「これはこれで」 and the 「それはそれとして」 below?

・・・まあ、それはそれとして、正解の答えがわかっても、どうすればあの「sprachgefühl」が身につけられるかという問題が残っています。

They both appear to have similar meanings.

Or would the sentence perhaps be better interpreted as such?

[これは] [これで少なくとも {相手が積極的だ} ってことはわかる]。

Answer

それはそれとして means "that aside, ..." "apart form that, ..."
Compare:
これはこれとして "that aside, ..." "setting this apart, ..." "apart from this, ..."

The これはこれで (≒ (これは)これなりに) here means "This (is good/okay, etc.) in its own way."
Compare:

それはそれで/(それは)それなりに = "That (is good/okay etc.) in its own way."
彼は彼で/(彼は)彼なりに =　"He (is trying hard / doing his best, etc.) in his own way."

I would parse your sentence this way:

[これはこれで][少なくとも{「相手が積極的だ」ってことは}]わかる。