CL can't match the WC for entertainment though that's not saying anything about the quality of the WC as you can have an enjoyable game at any level, and you're playing 6 games spaced out over 3 months in the CL which kills the momentum and buzz a bit so I think the WC group stages are better.
In terms of the actual quality of the football, the CL is of a higher standard, how could it not be? The players train together every day so know each other's games better.
I don't think the gulf is as big as is made out though, certainly not past the group stages.