Andersen was the best thing the series had, but the series probably could have survived without him. The biggest problem with the new episodes is that the Ori are inherently uninteresting.
They set the Ori up as so powerful, it's impossible to beat them with conventional tactics. With the gu'ald, even though they had superior technology, it was always possible to come up with some clever strategy to take them off guard and beat them with the technology they had. But the Ori are so powerful the only way to beat them is to find the next super-duper ancient weapon. Which, is boring, and is always going to be a rehash of the Lost City arc.