Here is a useful site listing various WWW sites contrasting the DSS and the Masoretic text, including:
Institue for Biblcal and scientific studies
Most Scholars saw the LXX as inferior to the Hebrew Bible called the Masoretic Text (MT). With the discovery of the Dead Sea Scrolls, this all changed. Ancient Hebrew scrolls were found that follow the LXX, not the Masoretic Text. The DSS showed that the LXX had an underlying Hebrew Text that was different from the MT.
Now Scholars think the LXX has important readings that are superior to the MT. The LXX is now very important in textual criticism of the Hebrew Bible. Let's look at some of the key differences between the LXX and the MT where the LXX seems to be superior.
Important Difference concerning the Prophetic Books:
Jeremiah
Jeremiah is one seventh shorter in the LXX than in the MT. This is the most dramatic difference between the LXX and MT. The LXX of Jeremiah probably reflects an earlier edition of the Book of Jeremiah. Not only is the LXX shorter, but the arrangement of verses is different.
The Dead Sea Scrolls 4QJer(b,d) are very similar to the LXX with the shorter text, and the different arrangement of verses.
In chapters 27-29 of the MT of Jeremiah the king of Babylon is spelled
Nebuchadnezzar while in the rest of the book it is in its original form
Nebuchadrezzar. The LXX only has
Nebuchadrezzar.
It should be noted that pseudopigraphal writings, and revisions were a common practice in ancient times. Their view of inspiration was also very different.
The MT editor added headings to prophecies, repeated sections, added new verses and sections, new details, new arrangements, and clarification of unclear passages. This most likely done after the exile.
In the LXX Jeremiah chapters 46-51 of the MT follow 25:13 of the LXX. These oracles against the nations are also put in a different order.
Ezekiel
There are many differences between the LXX and MT of Ezekiel. The LXX of Ezekiel is about 4-5% shorter than the MT. One example is Ezekiel 7:3-9. The LXX of Ezekiel seems to reflect a shorter Hebrew text. The MT being a later expanded edition. The MT adds parallel words and phrases, exegetical phrases, harmonization, and new material.
Ezekiel 36 is longer in the MT. P. Chester Beatty 967 of the LXX lacks verses 23-38. This implies that the Old Greek reflects an early stage of development of the Book of Ezekiel