Having finished season 1 I really enjoyed it. Highly recommend, even if you have absolutely no clue what the show is about. It is accessible to people unfamiliar with the source material.
This first season was only a taste of the series, so it would be really unfortunate if it doesn't get more seasons. But it is a real risk given Netflix's troubles. It cost upwards of $15 million per episode to make, which is comparable to the cost per episode of the final season of Game of Thrones. And it shows, the production value is pretty great and the special effects really bring the show to life.
I'm not sure if that figure of $15 million is the actual series average or the most expensive episode but I really do see the latter. A few of the episodes had a lot of visual effects but i'm skeptical it is the series average for sure.
Also, I think it'd be a huge loss for Netflix if they didn't renew for a second season. With Stranger Things ending with it's next season and a lot of great IPs getting dropped across all platforms, The Sandman has the potential to be a huge draw for Netflix, and I can't imagine it's cancellation doing any wonders for them subscription wise.