I have had some absolutely wonderful classes even with the correlated material.
If a lesson is read word-for-word or limited to "yes/no" responses, it's hellish; if it's used as a jumping off point for serious discussion, it's totally fine and can be incredibly enlightening and edifying. I've experienced both, so I know it's not all the fault of correlation.
Also, there were some really wacky things being preached and taught in the Church prior to correlation - when instruction basically was set at the local level. Correlation was the attempt to stop most of that wackiness and focus on the principles of the Gospel.
Serious question for contemplation:
Would you prefer the current material be used to focus on discussion of the concepts and principles in the manuals - or would you prefer having the local leaders in your wards or branches deciding what gets taught each Sunday in all classes?
If you tend to complain about correlation, consider the alternative - and how much the "craziness" of the past might bother you. (and, if you tend to downplay that craziness - or haven't experienced it like I have, think of the person in your ward, branch or stake whose views seem a bit "off" to you - and picture them controlling the instruction)
I will take correlation and the possibility of focused discussions about the core principles of the Gospel, every day and twice on Sunday - and that is true especially now with the new youth curriculum and "revelations in context" online materials.