What is your opinion of the early church Fathers in relation to the writings of the apostles in the Bible? How do you think we should interpret the one set of writings compared to the other set?
The Apostolic writers wrote under divine inspiration the Fathers didn't. This would be the main difference. This fact of course would not diminish in any way their profound erudition; their knowledge of early historical Christianity; of early Christian beliefs; and as regards the "Apostolic Fathers" their direct acquaintance with one or more of the actual Apostles which no one, and I mean no one!! can claim today.
"How do you think we should interpret the one set of writings compared to the other set?"
The Traditions found in the Fathers, as well as the Scriptures themselves should be interpreted in light of the Magisterium.
That which came from the Apostles themselves, repeated orally and written down later, has the same Apostolic authority, as St. Paul himself said: "So then, brethren, stand firm and hold to the traditions which you were taught by us, either by word of mouth or by letter" (2 Thess. 2:15).
The early Fathers -- even when they are not directly quoting the words of the Apostles-- are a valuable resource, especially in interpreting Scripture correctly.
They were often native speakers of the languages in which the Scriptures were written, or recognized by their contemporaries both as men of piety and as scholars, much closer to the Biblical times, mindset, and culture than we are.
For a comparison: suppose that there are some ambiguities of language or interpretation in the reading of Geoffrey Chaucer (Canterbury Tales.) It would be more relevant to look for commentaries from the 15th century, from near-contemporaries, than from a scholar whose knowledge of the English language and English culture is almost all from the 19th and 20th centuries.
The Fathers were highly respected by the believers in their day (which is why their writings have been carefully preserved from their day until now); the earliest ones were disciples and 1st-generation successors of the Apostles themselves; and they offer a rich insight into the thinking and practices of the faithful of early Church.