Bumping this question because I have the same one and feel the same way.
See my post above for the canonicity of the Marvel Netflix shows at this point. As for the quality of the Marvel Netflix shows and whether you should watch, most would agree the real answer is that you are dealing with a completely mixed bag, which is everyone's biggest criticism of the old Marvel TV division. For as much as we like to knock them for creating some of the worst Marvel shows of all-time like that of Inhumans or Iron Fist, at the same time, they also gave us some of the best we've ever seen, even soaring to heights the new MCU TV shows have yet to reach. They do deserve credit for that and am waiting personally for Feige to hit some of these similar quality levels. At the same time, at least Feige has been way more consistently good so far with what he has put out. With all that said, I figure the best thing at this point to show quality is by comparing them to what most have seen so far in Marvel Studios canon shows (Wandavision, Hawkeye, Loki, FATWS). Here is my breakdown:
Better than any of the MCU TV series we've seen thus far:
-Daredevil S1
-Daredevil S2 (first half of the season with the Punisher is better than second half, but still overall very good)
-Daredevil S3 (best Marvel TV season ever made)
-Punisher S1
On-Par with MCU TV series:
-Jessica Jones S1
A little worse to decently worse than any MCU TV series we've seen thus far:
-Luke Cage S1 (first half really good, second half not)
-Luke Cage S2
-Punisher S2
-Defenders
-Jessica Jones S2
-Iron Fist S2 (Finn Jones as Iron Fist is still really bad, but writing was better in general)
Way wores than any MCU TV series we've seen thus far:
-Iron Fist S1
-Jessica Jones S3
From a continuity perspective providing you don't want to watch all of these, I'd recommend watching all 3 Daredevil seasons with The Defenders in-between S2 and S3. For watching good quality shows purposes, I'd tag Punisher S1 on the end as well.