With regards to the excellence of the people of knowledge, the Shaykh Abdur-Rahmaan as Sa’dee rahimahullah mentions about the aayah:
<<Allah bears witness that none has the right to be worshipped except Him; and the angels and the people of knowledge (also bear witness to this). He maintains His creation with Justice. None has the right to be worshipped except Him, al Azeez, al Hakeem.>>
(Soorah aale ‘Imraan (3) aayah 18)
And in this aayah is (mentioning of) the virtue of knowledge and the people of knowledge – because Allah singled them out with making mention (of them) to the exclusion of other people; and linked their shahaadah (bearing witness) with His shahaadah and His angels’ shahaadah.
And He made their shahaadah to be from the greatest evidences and proofs for His Tawheed and His Religion and His Recompense.
And that it is obligatory for the mukallafeen (those who are Islamically accountable for their actions) to accept this just and truthful shahaadah.
(Tayseer ul Kareem ir Rahmaan of as Sa’dee)
With regards to the quote from ibn Mas`ood radi Allaahu ‘anhu about seeking knowledge from the senior scholars as opposed to the sighaar (the lesser ones), `Abdus Salaam ibn Burjis (d.1425AH) rahimahullaah comments:
And ibn Qutyabah rahimahullaahu ta’aala held the opinion that the sighaar (lesser ones) were the ones who were lesser in age. So he said about the narration of ibn Mas’ood mentioned above:
He (ibn Mas’ood) intended – that the people will not cease to be upon good as long as their scholars are the elders, and their scholars are not the youthful ones, because for the old man, the pleasure of youthfulness, and its self containment and its foolishness have disappeared from him. And he has taken on experience and knowledge as his companions.
So doubt does not come upon him in his knowledge; nor does desire get the better of him; nor does greed make him turn away and nor does Shaytan make him slip up with the errors of the young person. Thus with age there is dignity and honour and reverence.
And it may be these matters– matters which the old person is secure from – enter upon the youth; so when they enter upon him, and he gives fataawaa (Islamic rulings), he is destroyed and he destroys (others).
(to the end of his statement) 
(Awaa-iq ut talab of ‘Abdus Salaam ibn Burjiss rahimahullaah pages 24, translated by Nasser ibn Najam)
 ‘Naseehah ahl il hadeeth’ page 16