I really struggled with the first few seasons of BCS any time it was about Chuck (to the point I stopped watching for a few years after S1), didn't find that element interesting in the slightest, the rest of it was great. S4 onwards for me it really hit it's stride and finished it a few weeks back.I put off watching BCS and see it has concluded with S6; perfect time to start!
I'm just about to finish S2 and am finding BCS to be excellent viewing.
There are maybe 2 or 3 episodes that reached the greatness of BB but overall - it never managed to maintain that level.
I might be in a minority but i'd love a series about Mike, I found every minute with him on screen absolutely compelling viewing. However to find anyone as good as Jonathan Banks to play the role will be impossible. Also due to his age, it could never really happen.