I think it's equally good, but I can appreciate that it must be far more challenging to write.

From a writing perspective, Breaking Bad was amazing because they somehow created a very good story arc for the entire series, despite having no idea (at least initially) how many seasons it might last. Better Call Saul has to maintain continuity with a story that's already been written. It's like trying painting yourself into a corner and then exiting the room without leaving a footprint.