I can't speak to what audiences find boring now -- I know that I watched it as a kid when my attention span was not at its peak, and I found the pacing to be just fine. (I did see the much-panned version with the narration first.)

I've re-watched it quite a few times and find new things to enjoy each time. The aesthetic is hugely influential, but it also has a fantastic cast and superb acting. The soundtrack is also perfect.

The love story between Deckard and Rachel is ham-fisted, I will grant that, and if I were giving notes I'd say we need to see more of the backstory for the replicants. But IMO it succeeds far better than the book.