The real authority in religious matters is the most learned scholars who are known as Maraaji' of Taqleed. Their opinion is based on comprehensive research in Quran, Hadeeth, Intellect and Ijmaa' (consensus). Among them, the verdict of the most learned is to be taken.
Irfan and Sufism are two terms about which there are many different opinions among the scholars.
Many think that spiritual upliftment can be achieved through Sufism. This is not the real picture which we read it in Quran and Hadeeth and life of the Prophet (SAWA) and Ahlul Bayt (AS). Spiritual upliftment is achieved by self control and self purification acts,like thinking, fasting, night prayers, reciting Quran and Du'a, strengthening our will power, remembering our near future (tomorrow) after this life and above all, humbleness in following the Prophet and his Ahlul Bayt(AS). These acts lead to Spiritual purification do not need any of ways of Sufism.
Followers of Ahlul Bayt (AS) have very rich and comprehensive spiritual materials which is more than sufficient to provide them with spiritual purification in every step and degree. That is why you find most of the followers of Ahlul Bayt (AS) and their scholars not involved in Sufi ways while you see that many of our Sunni brothers seek spiritual purification through Sufi ways because they do not have in their books the great treasures which we have from Ahlul Bayt (AS). Just see as an example the book known as Sahifa Sajjadia which has number of supplications narrated from Imam Al-Sajjad (AS) as well other supplications from other Imams like Du'a Kumail, Du'a Al-Sabah, Du'a Abi Hamza al-Thimaali, Du'a Jawshan and many other supplications.
Many non Shia scholars were amazed when they came across supplications narrated from Ahlul Bayt and found it unique and with no similar in the the whole Muslim books.