So, I've watched the second season of Good Omens, twice actually since the its release on Friday, and I loved it!  First off, I will say that season 1 is the better season of the two, it's has a better plot and is more tightly paced.  But, if you love Ineffable Husbands at all I recommend you watch it.  A few professional reviews have said it feels very much like watching fanfiction, and I think that is a very apt description.  We get more of Aziraphale and Crowley and their journeys and shenanigans throughout history.  We get outsider POV on Aziraphale and Crowley from Aziraphale's neighbours.  We get to see Crowley before the Fall!  We get affectionate looks, little touches, and dancing!  So many little story ideas and head canons I've seen floating around the past four years show up in this season. 

That being said there is still issues between the two of them that have not been resolved, and I could see many fans being disappointed that the two of them haven't made more progress.  Also, a warning for a lot of angst right at the very end of the season, and the angst is not resolved.  The main issue of the season does get resolved, but they are obviously setting things up for a season three.  I have had a couple mutuals decide to skip the last fifteen minutes, so they can be happy and then they said they will watch the last fifteen minutes just before season 3 eventually comes out.  I don't think I could do that, but to each their own.

Anyways, you could just watch season 1 and be happy with that as the ending, but if you love Ineffable Husbands and are okay with an angsty ending then give it a watch.