Part of the reason for using LXX for the NT OT quotes lies in the idea that the Apostles and (at least the Gentile believers) used the LXX instead of the Hebrew for their daily use. Many of the OT quotes in the NT are much closer to the LXX than the Hebrew.
Personally, I prefer the Hebrew, though that doesn't stop me from making forays into Brenton's English Septuagint and even the occasional venture into James Murdock New Testament (A translation of the Peshito Syriac New Testament into English by James Murdock.) for a look at a very early translation of the NT.
Thus says the LORD, "Let not a wise man boast of his wisdom, and let not the mighty man boast of his might, let not a rich man boast of his riches; but let him who boasts boast of this, that he understands and knows Me, (Jeremiah 9:23-24a)
"Defenders of the faith are inclined to be bitter until they learn to walk in the light of the Lord. When you have learned to walk in the light of the Lord, bitterness and contention are impossible." --Oswald Chambers, in Biblical Psychology from The Quotable Oswald Chambers.